Python Documentation contents

• What’s New in Python
  • What’s New In Python 3.4
    • Summary – Release Highlights
    • New Features
      • PEP 453: Explicit Bootstrapping of PIP in Python Installations
        • Bootstrapping pip By Default
        • Documentation Changes
      • PEP 446: Newly Created File Descriptors Are Non-Inheritable
      • Improvements to Codec Handling
      • PEP 451: A ModuleSpec Type for the Import System
      • Other Language Changes
    • New Modules
      • asyncio
      • ensurepip
      • enum
      • pathlib
      • selectors
      • statistics
      • tracemalloc
    • Improved Modules
      • abc
      • aifc
      • argparse
      • audioop
      • base64
      • collections
      • colorsys
      • contextlib
      • dbm
      • dis
      • doctest
      • email
      • filecmp
      • functools
      • gc
      • glob
      • hashlib
      • hmac
      • html
      • http
      • idlelib and IDLE
      • importlib
      • inspect
      • ipaddress
      • logging
      • marshal
      • mmap
      • multiprocessing
      • operator
      • os
      • pdb
      • pickle
      • plistlib
      • poplib
      • pprint
      • pty
      • pydoc
      • re
      • resource
      • select
      • shelve
      • shutil
      • smtpd
      • smtplib
      • socket
      • sqlite3
      • ssl
      • stat
      • struct
      • subprocess
      • sunau
      • sys
      • tarfile
      • textwrap
      • threading
      • traceback
      • types
      • urllib
      • unittest
      • venv
      • wave
      • weakref
      • xml.etree
      • zipfile
    • CPython Implementation Changes
      • PEP 445: Customization of CPython Memory Allocators
      • PEP 442: Safe Object Finalization
      • PEP 456: Secure and Interchangeable Hash Algorithm
      • PEP 436: Argument Clinic
      • Other Build and C API Changes
      • Other Improvements
      • Significant Optimizations
    • Deprecated
      • Deprecations in the Python API
      • Deprecated Features
    • Removed
      • Operating Systems No Longer Supported
      • API and Feature Removals
      • Code Cleanups
    • Porting to Python 3.4
      • Changes in ‘python’ Command Behavior
      • Changes in the Python API
      • Changes in the C API
    • Changed in 3.4.3
      • PEP 476: Enabling certificate verification by default for stdlib http clients
  • What’s New In Python 3.3
    • Summary – Release highlights
    • PEP 405: Virtual Environments
    • PEP 420: Implicit Namespace Packages
    • PEP 3118: New memoryview implementation and buffer protocol documentation
      • Features
      • API changes
    • PEP 393: Flexible String Representation
      • Functionality
      • Performance and resource usage
    • PEP 397: Python Launcher for Windows
    • PEP 3151: Reworking the OS and IO exception hierarchy
    • PEP 380: Syntax for Delegating to a Subgenerator
    • PEP 409: Suppressing exception context
    • PEP 414: Explicit Unicode literals
    • PEP 3155: Qualified name for classes and functions
    • PEP 412: Key-Sharing Dictionary
    • PEP 362: Function Signature Object
    • PEP 421: Adding sys.implementation
      • SimpleNamespace
    • Using importlib as the Implementation of Import
      • New APIs
      • Visible Changes
    • Other Language Changes
    • A Finer-Grained Import Lock
    • Builtin functions and types
    • New Modules
      • faulthandler
      • ipaddress
      • lzma
    • Improved Modules
      • abc
      • array
      • base64
      • binascii
      • bz2
      • codecs
      • collections
      • contextlib
      • crypt
      • curses
      • datetime
      • decimal
        • Features
        • API changes
      • email
        • Policy Framework
        • Provisional Policy with New Header API
        • Other API Changes
      • ftplib
      • functools
      • gc
      • hmac
      • http
      • html
      • imaplib
      • inspect
      • io
      • itertools
      • logging
      • math
      • mmap
      • multiprocessing
      • nntplib
      • os
      • pdb
      • pickle
      • pydoc
      • re
      • sched
      • select
      • shlex
      • shutil
      • signal
      • smtpd
      • smtplib
      • socket
      • socketserver
      • sqlite3
      • ssl
      • stat
      • struct
      • subprocess
      • sys
      • tarfile
      • tempfile
      • textwrap
      • threading
      • time
      • types
      • unittest
      • urllib
      • webbrowser
      • xml.etree.ElementTree
      • zlib
    • Optimizations
    • Build and C API Changes
    • Deprecated
      • Unsupported Operating Systems
      • Deprecated Python modules, functions and methods
      • Deprecated functions and types of the C API
      • Deprecated features
    • Porting to Python 3.3
      • Porting Python code
      • Porting C code
      • Building C extensions
      • Command Line Switch Changes
  • What’s New In Python 3.2
    • PEP 384: Defining a Stable ABI
    • PEP 389: Argparse Command Line Parsing Module
    • PEP 391: Dictionary Based Configuration for Logging
    • PEP 3148: The concurrent.futures module
    • PEP 3147: PYC Repository Directories
    • PEP 3149: ABI Version Tagged .so Files
    • PEP 3333: Python Web Server Gateway Interface v1.0.1
    • Other Language Changes
    • New, Improved, and Deprecated Modules
      • email
      • elementtree
      • functools
      • itertools
      • collections
      • threading
      • datetime and time
      • math
      • abc
      • io
      • reprlib
      • logging
      • csv
      • contextlib
      • decimal and fractions
      • ftp
      • popen
      • select
      • gzip and zipfile
      • tarfile
      • hashlib
      • ast
      • os
      • shutil
      • sqlite3
      • html
      • socket
      • ssl
      • nntp
      • certificates
      • imaplib
      • http.client
      • unittest
      • random
      • poplib
      • asyncore
      • tempfile
      • inspect
      • pydoc
      • dis
      • dbm
      • ctypes
      • site
      • sysconfig
      • pdb
      • configparser
      • urllib.parse
      • mailbox
      • turtledemo
    • Multi-threading
    • Optimizations
    • Unicode
    • Codecs
    • Documentation
    • IDLE
    • Code Repository
    • Build and C API Changes
    • Porting to Python 3.2
  • What’s New In Python 3.1
    • PEP 372: Ordered Dictionaries
    • PEP 378: Format Specifier for Thousands Separator
    • Other Language Changes
    • New, Improved, and Deprecated Modules
    • Optimizations
    • IDLE
    • Build and C API Changes
    • Porting to Python 3.1
  • What’s New In Python 3.0
    • Common Stumbling Blocks
      • Print Is A Function
      • Views And Iterators Instead Of Lists
      • Ordering Comparisons
      • Integers
      • Text Vs. Data Instead Of Unicode Vs. 8-bit
    • Overview Of Syntax Changes
      • New Syntax
      • Changed Syntax
      • Removed Syntax
    • Changes Already Present In Python 2.6
    • Library Changes
    • PEP 3101: A New Approach To String Formatting
    • Changes To Exceptions
    • Miscellaneous Other Changes
      • Operators And Special Methods
      • Builtins
    • Build and C API Changes
    • Performance
    • Porting To Python 3.0
  • What’s New in Python 2.7
    • The Future for Python 2.x
    • Changes to the Handling of Deprecation Warnings
    • Python 3.1 Features
    • PEP 372: Adding an Ordered Dictionary to collections
    • PEP 378: Format Specifier for Thousands Separator
    • PEP 389: The argparse Module for Parsing Command Lines
    • PEP 391: Dictionary-Based Configuration For Logging
    • PEP 3106: Dictionary Views
    • PEP 3137: The memoryview Object
    • Other Language Changes
      • Interpreter Changes
      • Optimizations
    • New and Improved Modules
      • New module: importlib
      • New module: sysconfig
      • ttk: Themed Widgets for Tk
      • Updated module: unittest
      • Updated module: ElementTree 1.3
    • Build and C API Changes
      • Capsules
      • Port-Specific Changes: Windows
      • Port-Specific Changes: Mac OS X
      • Port-Specific Changes: FreeBSD
    • Other Changes and Fixes
    • Porting to Python 2.7
    • New Features Added to Python 2.7 Maintenance Releases
      • PEP 434: IDLE Enhancement Exception for All Branches
      • PEP 466: Network Security Enhancements for Python 2.7
    • Acknowledgements
  • What’s New in Python 2.6
    • Python 3.0
    • Changes to the Development Process
      • New Issue Tracker: Roundup
      • New Documentation Format: reStructuredText Using Sphinx
    • PEP 343: The ‘with’ statement
      • Writing Context Managers
      • The contextlib module
    • PEP 366: Explicit Relative Imports From a Main Module
    • PEP 370: Per-user site-packages Directory
    • PEP 371: The multiprocessing Package
    • PEP 3101: Advanced String Formatting
    • PEP 3105: print As a Function
    • PEP 3110: Exception-Handling Changes
    • PEP 3112: Byte Literals
    • PEP 3116: New I/O Library
    • PEP 3118: Revised Buffer Protocol
    • PEP 3119: Abstract Base Classes
    • PEP 3127: Integer Literal Support and Syntax
    • PEP 3129: Class Decorators
    • PEP 3141: A Type Hierarchy for Numbers
      • The fractions Module
    • Other Language Changes
      • Optimizations
      • Interpreter Changes
    • New and Improved Modules
      • The ast module
      • The future_builtins module
      • The json module: JavaScript Object Notation
      • The plistlib module: A Property-List Parser
      • ctypes Enhancements
      • Improved SSL Support
    • Deprecations and Removals
    • Build and C API Changes
      • Port-Specific Changes: Windows
      • Port-Specific Changes: Mac OS X
      • Port-Specific Changes: IRIX
    • Porting to Python 2.6
    • Acknowledgements
  • What’s New in Python 2.5
    • PEP 308: Conditional Expressions
    • PEP 309: Partial Function Application
    • PEP 314: Metadata for Python Software Packages v1.1
    • PEP 328: Absolute and Relative Imports
    • PEP 338: Executing Modules as Scripts
    • PEP 341: Unified try/except/finally
    • PEP 342: New Generator Features
    • PEP 343: The ‘with’ statement
      • Writing Context Managers
      • The contextlib module
    • PEP 352: Exceptions as New-Style Classes
    • PEP 353: Using ssize_t as the index type
    • PEP 357: The ‘__index__’ method
    • Other Language Changes
      • Interactive Interpreter Changes
      • Optimizations
    • New, Improved, and Removed Modules
      • The ctypes package
      • The ElementTree package
      • The hashlib package
      • The sqlite3 package
      • The wsgiref package
    • Build and C API Changes
      • Port-Specific Changes
    • Porting to Python 2.5
    • Acknowledgements
  • What’s New in Python 2.4
    • PEP 218: Built-In Set Objects
    • PEP 237: Unifying Long Integers and Integers
    • PEP 289: Generator Expressions
    • PEP 292: Simpler String Substitutions
    • PEP 318: Decorators for Functions and Methods
    • PEP 322: Reverse Iteration
    • PEP 324: New subprocess Module
    • PEP 327: Decimal Data Type
      • Why is Decimal needed?
      • The Decimal type
      • The Context type
    • PEP 328: Multi-line Imports
    • PEP 331: Locale-Independent Float/String Conversions
    • Other Language Changes
      • Optimizations
    • New, Improved, and Deprecated Modules
      • cookielib
      • doctest
    • Build and C API Changes
      • Port-Specific Changes
    • Porting to Python 2.4
    • Acknowledgements
  • What’s New in Python 2.3
    • PEP 218: A Standard Set Datatype
    • PEP 255: Simple Generators
    • PEP 263: Source Code Encodings
    • PEP 273: Importing Modules from ZIP Archives
    • PEP 277: Unicode file name support for Windows NT
    • PEP 278: Universal Newline Support
    • PEP 279: enumerate()
    • PEP 282: The logging Package
    • PEP 285: A Boolean Type
    • PEP 293: Codec Error Handling Callbacks
    • PEP 301: Package Index and Metadata for Distutils
    • PEP 302: New Import Hooks
    • PEP 305: Comma-separated Files
    • PEP 307: Pickle Enhancements
    • Extended Slices
    • Other Language Changes
      • String Changes
      • Optimizations
    • New, Improved, and Deprecated Modules
      • Date/Time Type
      • The optparse Module
    • Pymalloc: A Specialized Object Allocator
    • Build and C API Changes
      • Port-Specific Changes
    • Other Changes and Fixes
    • Porting to Python 2.3
    • Acknowledgements
  • What’s New in Python 2.2
    • Introduction
    • PEPs 252 and 253: Type and Class Changes
      • Old and New Classes
      • Descriptors
      • Multiple Inheritance: The Diamond Rule
      • Attribute Access
      • Related Links
    • PEP 234: Iterators
    • PEP 255: Simple Generators
    • PEP 237: Unifying Long Integers and Integers
    • PEP 238: Changing the Division Operator
    • Unicode Changes
    • PEP 227: Nested Scopes
    • New and Improved Modules
    • Interpreter Changes and Fixes
    • Other Changes and Fixes
    • Acknowledgements
  • What’s New in Python 2.1
    • Introduction
    • PEP 227: Nested Scopes
    • PEP 236: __future__ Directives
    • PEP 207: Rich Comparisons
    • PEP 230: Warning Framework
    • PEP 229: New Build System
    • PEP 205: Weak References
    • PEP 232: Function Attributes
    • PEP 235: Importing Modules on Case-Insensitive Platforms
    • PEP 217: Interactive Display Hook
    • PEP 208: New Coercion Model
    • PEP 241: Metadata in Python Packages
    • New and Improved Modules
    • Other Changes and Fixes
    • Acknowledgements
  • What’s New in Python 2.0
    • Introduction
    • What About Python 1.6?
    • New Development Process
    • Unicode
    • List Comprehensions
    • Augmented Assignment
    • String Methods
    • Garbage Collection of Cycles
    • Other Core Changes
      • Minor Language Changes
      • Changes to Built-in Functions
    • Porting to 2.0
    • Extending/Embedding Changes
    • Distutils: Making Modules Easy to Install
    • XML Modules
      • SAX2 Support
      • DOM Support
      • Relationship to PyXML
    • Module changes
    • New modules
    • IDLE Improvements
    • Deleted and Deprecated Modules
    • Acknowledgements
  • Changelog
    • Python 3.4.4rc1
      • Core and Builtins
      • Library
      • IDLE
      • Tests
      • Build
      • C API
      • Documentation
      • Tools/Demos
    • Python 3.4.3
      • Core and Builtins
      • Library
      • IDLE
      • Tests
      • Build
      • C API
      • Documentation
      • Tools/Demos
      • Windows
    • Python 3.4.2
      • Library
    • Python 3.4.2rc1
      • Core and Builtins
      • Library
      • Extension Modules
      • Build
      • IDLE
      • Tests
      • Documentation
      • Windows
      • Tools/Demos
    • Python 3.4.1
      • Core and Builtins
      • Library
      • Tests
      • IDLE
    • Python 3.4.1rc1
      • Core and Builtins
      • Library
      • Extension Modules
      • IDLE
      • Build
      • C API
      • Documentation
      • Tests
      • Tools/Demos
    • Python 3.4.0
      • Library
      • Documentation
    • Python 3.4.0 release candidate 3
      • Core and Builtins
      • Library
      • Build
    • Python 3.4.0 release candidate 2
      • Core and Builtins
      • Library
      • Build
    • Python 3.4.0 release candidate 1
      • Core and Builtins
      • Library
      • IDLE
      • Tests
      • Tools/Demos
      • Build
      • C-API
      • Documentation
    • Python 3.4.0 Beta 3
      • Core and Builtins
      • Library
      • IDLE
      • Tests
      • Tools/Demos
      • Build
    • Python 3.4.0 Beta 2
      • Core and Builtins
      • Library
      • IDLE
      • Tests
      • Build
      • Documentation
      • Tools/Demos
    • Python 3.4.0 Beta 1
      • Core and Builtins
      • Library
      • Tests
      • Documentation
      • Build
      • Tools/Demos
    • Python 3.4.0 Alpha 4
      • Core and Builtins
      • Library
      • C API
      • Tests
      • Documentation
      • Build
    • Python 3.4.0 Alpha 3
      • Core and Builtins
      • Library
      • Tests
      • IDLE
      • Documentation
      • Build
      • Tools/Demos
    • Python 3.4.0 Alpha 2
      • Core and Builtins
      • Library
      • Tests
      • IDLE
      • Documentation
      • Build
      • Tools/Demos
    • Python 3.4.0 Alpha 1
      • Core and Builtins
      • Library
      • IDLE
      • Tests
      • Build
      • C-API
      • Documentation
      • Tools/Demos
      • Windows
    • Python 3.3.0
      • Core and Builtins
      • Extension Modules
    • Python 3.3.0 Release Candidate 3
      • Core and Builtins
      • Library
      • Extension Modules
    • Python 3.3.0 Release Candidate 2
      • Core and Builtins
      • Library
      • Build
      • Documentation
    • Python 3.3.0 Release Candidate 1
      • Core and Builtins
      • Library
      • IDLE
      • Documentation
      • Tests
      • Build
    • Python 3.3.0 Beta 2
      • Core and Builtins
      • Library
      • C API
      • Extension Modules
      • IDLE
      • Tools/Demos
      • Documentation
      • Tests
      • Build
    • Python 3.3.0 Beta 1
      • Core and Builtins
      • Library
      • C-API
      • Extension Modules
      • IDLE
      • Documentation
      • Tests
      • Build
    • Python 3.3.0 Alpha 4
      • Core and Builtins
      • Library
      • IDLE
      • Tools/Demos
      • Build
      • C-API
      • Documentation
    • Python 3.3.0 Alpha 3
      • Core and Builtins
      • Library
      • Build
      • Tests
      • IDLE
      • Tools / Demos
      • C-API
    • Python 3.3.0 Alpha 2
      • Core and Builtins
      • Library
      • Build
      • Documentation
      • Extension Modules
      • Tests
    • Python 3.3.0 Alpha 1
      • Core and Builtins
      • Library
      • Build
      • IDLE
      • Tools/Demos
      • Extension Modules
      • Tests
      • C-API
      • Documentation
• The Python Tutorial
  • 1. Whetting Your Appetite
  • 2. Using the Python Interpreter
    • 2.1. Invoking the Interpreter
      • 2.1.1. Argument Passing
      • 2.1.2. Interactive Mode
    • 2.2. The Interpreter and Its Environment
      • 2.2.1. Source Code Encoding
  • 3. An Informal Introduction to Python
    • 3.1. Using Python as a Calculator
      • 3.1.1. Numbers
      • 3.1.2. Strings
      • 3.1.3. Lists
    • 3.2. First Steps Towards Programming
  • 4. More Control Flow Tools
    • 4.1. if Statements
    • 4.2. for Statements
    • 4.3. The range() Function
    • 4.4. break and continue Statements, and else Clauses on Loops
    • 4.5. pass Statements
    • 4.6. Defining Functions
    • 4.7. More on Defining Functions
      • 4.7.1. Default Argument Values
      • 4.7.2. Keyword Arguments
      • 4.7.3. Arbitrary Argument Lists
      • 4.7.4. Unpacking Argument Lists
      • 4.7.5. Lambda Expressions
      • 4.7.6. Documentation Strings
      • 4.7.7. Function Annotations
    • 4.8. Intermezzo: Coding Style
  • 5. Data Structures
    • 5.1. More on Lists
      • 5.1.1. Using Lists as Stacks
      • 5.1.2. Using Lists as Queues
      • 5.1.3. List Comprehensions
      • 5.1.4. Nested List Comprehensions
    • 5.2. The del statement
    • 5.3. Tuples and Sequences
    • 5.4. Sets
    • 5.5. Dictionaries
    • 5.6. Looping Techniques
    • 5.7. More on Conditions
    • 5.8. Comparing Sequences and Other Types
  • 6. Modules
    • 6.1. More on Modules
      • 6.1.1. Executing modules as scripts
      • 6.1.2. The Module Search Path
      • 6.1.3. “Compiled” Python files
    • 6.2. Standard Modules
    • 6.3. The dir() Function
    • 6.4. Packages
      • 6.4.1. Importing * From a Package
      • 6.4.2. Intra-package References
      • 6.4.3. Packages in Multiple Directories
  • 7. Input and Output
    • 7.1. Fancier Output Formatting
      • 7.1.1. Old string formatting
    • 7.2. Reading and Writing Files
      • 7.2.1. Methods of File Objects
      • 7.2.2. Saving structured data with json
  • 8. Errors and Exceptions
    • 8.1. Syntax Errors
    • 8.2. Exceptions
    • 8.3. Handling Exceptions
    • 8.4. Raising Exceptions
    • 8.5. User-defined Exceptions
    • 8.6. Defining Clean-up Actions
    • 8.7. Predefined Clean-up Actions
  • 9. Classes
    • 9.1. A Word About Names and Objects
    • 9.2. Python Scopes and Namespaces
      • 9.2.1. Scopes and Namespaces Example
    • 9.3. A First Look at Classes
      • 9.3.1. Class Definition Syntax
      • 9.3.2. Class Objects
      • 9.3.3. Instance Objects
      • 9.3.4. Method Objects
      • 9.3.5. Class and Instance Variables
    • 9.4. Random Remarks
    • 9.5. Inheritance
      • 9.5.1. Multiple Inheritance
    • 9.6. Private Variables
    • 9.7. Odds and Ends
    • 9.8. Exceptions Are Classes Too
    • 9.9. Iterators
    • 9.10. Generators
    • 9.11. Generator Expressions
  • 10. Brief Tour of the Standard Library
    • 10.1. Operating System Interface
    • 10.2. File Wildcards
    • 10.3. Command Line Arguments
    • 10.4. Error Output Redirection and Program Termination
    • 10.5. String Pattern Matching
    • 10.6. Mathematics
    • 10.7. Internet Access
    • 10.8. Dates and Times
    • 10.9. Data Compression
    • 10.10. Performance Measurement
    • 10.11. Quality Control
    • 10.12. Batteries Included
  • 11. Brief Tour of the Standard Library – Part II
    • 11.1. Output Formatting
    • 11.2. Templating
    • 11.3. Working with Binary Data Record Layouts
    • 11.4. Multi-threading
    • 11.5. Logging
    • 11.6. Weak References
    • 11.7. Tools for Working with Lists
    • 11.8. Decimal Floating Point Arithmetic
  • 12. Virtual Environments and Packages
    • 12.1. Introduction
    • 12.2. Creating Virtual Environments
    • 12.3. Managing Packages with pip
  • 13. What Now?
  • 14. Interactive Input Editing and History Substitution
    • 14.1. Tab Completion and History Editing
    • 14.2. Alternatives to the Interactive Interpreter
  • 15. Floating Point Arithmetic: Issues and Limitations
    • 15.1. Representation Error
  • 16. Appendix
    • 16.1. Interactive Mode
      • 16.1.1. Error Handling
      • 16.1.2. Executable Python Scripts
      • 16.1.3. The Interactive Startup File
      • 16.1.4. The Customization Modules
• Python Setup and Usage
  • 1. Command line and environment
    • 1.1. Command line
      • 1.1.1. Interface options
      • 1.1.2. Generic options
      • 1.1.3. Miscellaneous options
      • 1.1.4. Options you shouldn’t use
    • 1.2. Environment variables
      • 1.2.1. Debug-mode variables
  • 2. Using Python on Unix platforms
    • 2.1. Getting and installing the latest version of Python
      • 2.1.1. On Linux
      • 2.1.2. On FreeBSD and OpenBSD
      • 2.1.3. On OpenSolaris
    • 2.2. Building Python
    • 2.3. Python-related paths and files
    • 2.4. Miscellaneous
    • 2.5. Editors
  • 3. Using Python on Windows
    • 3.1. Installing Python
    • 3.2. Alternative bundles
    • 3.3. Configuring Python
      • 3.3.1. Excursus: Setting environment variables
      • 3.3.2. Finding the Python executable
      • 3.3.3. Finding modules
      • 3.3.4. Executing scripts
      • 3.3.5. Executing scripts without the Python launcher
    • 3.4. Python Launcher for Windows
      • 3.4.1. Getting started
        • 3.4.1.1. From the command-line
        • 3.4.1.2. From a script
        • 3.4.1.3. From file associations
      • 3.4.2. Shebang Lines
      • 3.4.3. Arguments in shebang lines
      • 3.4.4. Customization
        • 3.4.4.1. Customization via INI files
        • 3.4.4.2. Customizing default Python versions
      • 3.4.5. Diagnostics
    • 3.5. Additional modules
      • 3.5.1. PyWin32
      • 3.5.2. cx_Freeze
      • 3.5.3. WConio
    • 3.6. Compiling Python on Windows
    • 3.7. Other resources
  • 4. Using Python on a Macintosh
    • 4.1. Getting and Installing MacPython
      • 4.1.1. How to run a Python script
      • 4.1.2. Running scripts with a GUI
      • 4.1.3. Configuration
    • 4.2. The IDE
    • 4.3. Installing Additional Python Packages
    • 4.4. GUI Programming on the Mac
    • 4.5. Distributing Python Applications on the Mac
    • 4.6. Other Resources
  • 5. Additional Tools and Scripts
    • 5.1. pyvenv - Creating virtual environments
• The Python Language Reference
  • 1. Introduction
    • 1.1. Alternate Implementations
    • 1.2. Notation
  • 2. Lexical analysis
    • 2.1. Line structure
      • 2.1.1. Logical lines
      • 2.1.2. Physical lines
      • 2.1.3. Comments
      • 2.1.4. Encoding declarations
      • 2.1.5. Explicit line joining
      • 2.1.6. Implicit line joining
      • 2.1.7. Blank lines
      • 2.1.8. Indentation
      • 2.1.9. Whitespace between tokens
    • 2.2. Other tokens
    • 2.3. Identifiers and keywords
      • 2.3.1. Keywords
      • 2.3.2. Reserved classes of identifiers
    • 2.4. Literals
      • 2.4.1. String and Bytes literals
      • 2.4.2. String literal concatenation
      • 2.4.3. Numeric literals
      • 2.4.4. Integer literals
      • 2.4.5. Floating point literals
      • 2.4.6. Imaginary literals
    • 2.5. Operators
    • 2.6. Delimiters
  • 3. Data model
    • 3.1. Objects, values and types
    • 3.2. The standard type hierarchy
    • 3.3. Special method names
      • 3.3.1. Basic customization
      • 3.3.2. Customizing attribute access
        • 3.3.2.1. Implementing Descriptors
        • 3.3.2.2. Invoking Descriptors
        • 3.3.2.3. __slots__
          • 3.3.2.3.1. Notes on using __slots__
      • 3.3.3. Customizing class creation
        • 3.3.3.1. Determining the appropriate metaclass
        • 3.3.3.2. Preparing the class namespace
        • 3.3.3.3. Executing the class body
        • 3.3.3.4. Creating the class object
        • 3.3.3.5. Metaclass example
      • 3.3.4. Customizing instance and subclass checks
      • 3.3.5. Emulating callable objects
      • 3.3.6. Emulating container types
      • 3.3.7. Emulating numeric types
      • 3.3.8. With Statement Context Managers
      • 3.3.9. Special method lookup
  • 4. Execution model
    • 4.1. Naming and binding
      • 4.1.1. Interaction with dynamic features
    • 4.2. Exceptions
  • 5. The import system
    • 5.1. importlib
    • 5.2. Packages
      • 5.2.1. Regular packages
      • 5.2.2. Namespace packages
    • 5.3. Searching
      • 5.3.1. The module cache
      • 5.3.2. Finders and loaders
      • 5.3.3. Import hooks
      • 5.3.4. The meta path
    • 5.4. Loading
      • 5.4.1. Loaders
      • 5.4.2. Submodules
      • 5.4.3. Module spec
      • 5.4.4. Import-related module attributes
      • 5.4.5. module.__path__
      • 5.4.6. Module reprs
    • 5.5. The Path Based Finder
      • 5.5.1. Path entry finders
      • 5.5.2. Path entry finder protocol
    • 5.6. Replacing the standard import system
    • 5.7. Special considerations for __main__
      • 5.7.1. __main__.__spec__
    • 5.8. Open issues
    • 5.9. References
  • 6. Expressions
    • 6.1. Arithmetic conversions
    • 6.2. Atoms
      • 6.2.1. Identifiers (Names)
      • 6.2.2. Literals
      • 6.2.3. Parenthesized forms
      • 6.2.4. Displays for lists, sets and dictionaries
      • 6.2.5. List displays
      • 6.2.6. Set displays
      • 6.2.7. Dictionary displays
      • 6.2.8. Generator expressions
      • 6.2.9. Yield expressions
        • 6.2.9.1. Generator-iterator methods
        • 6.2.9.2. Examples
    • 6.3. Primaries
      • 6.3.1. Attribute references
      • 6.3.2. Subscriptions
      • 6.3.3. Slicings
      • 6.3.4. Calls
    • 6.4. The power operator
    • 6.5. Unary arithmetic and bitwise operations
    • 6.6. Binary arithmetic operations
    • 6.7. Shifting operations
    • 6.8. Binary bitwise operations
    • 6.9. Comparisons
    • 6.10. Boolean operations
    • 6.11. Conditional expressions
    • 6.12. Lambdas
    • 6.13. Expression lists
    • 6.14. Evaluation order
    • 6.15. Operator precedence
  • 7. Simple statements
    • 7.1. Expression statements
    • 7.2. Assignment statements
      • 7.2.1. Augmented assignment statements
    • 7.3. The assert statement
    • 7.4. The pass statement
    • 7.5. The del statement
    • 7.6. The return statement
    • 7.7. The yield statement
    • 7.8. The raise statement
    • 7.9. The break statement
    • 7.10. The continue statement
    • 7.11. The import statement
      • 7.11.1. Future statements
    • 7.12. The global statement
    • 7.13. The nonlocal statement
  • 8. Compound statements
    • 8.1. The if statement
    • 8.2. The while statement
    • 8.3. The for statement
    • 8.4. The try statement
    • 8.5. The with statement
    • 8.6. Function definitions
    • 8.7. Class definitions
  • 9. Top-level components
    • 9.1. Complete Python programs
    • 9.2. File input
    • 9.3. Interactive input
    • 9.4. Expression input
  • 10. Full Grammar specification
• The Python Standard Library
  • 1. Introduction
  • 2. Built-in Functions
  • 3. Built-in Constants
    • 3.1. Constants added by the site module
  • 4. Built-in Types
    • 4.1. Truth Value Testing
    • 4.2. Boolean Operations — and, or, not
    • 4.3. Comparisons
    • 4.4. Numeric Types — int, float, complex
      • 4.4.1. Bitwise Operations on Integer Types
      • 4.4.2. Additional Methods on Integer Types
      • 4.4.3. Additional Methods on Float
      • 4.4.4. Hashing of numeric types
    • 4.5. Iterator Types
      • 4.5.1. Generator Types
    • 4.6. Sequence Types — list, tuple, range
      • 4.6.1. Common Sequence Operations
      • 4.6.2. Immutable Sequence Types
      • 4.6.3. Mutable Sequence Types
      • 4.6.4. Lists
      • 4.6.5. Tuples
      • 4.6.6. Ranges
    • 4.7. Text Sequence Type — str
      • 4.7.1. String Methods
      • 4.7.2. printf-style String Formatting
    • 4.8. Binary Sequence Types — bytes, bytearray, memoryview
      • 4.8.1. Bytes
      • 4.8.2. Bytearray Objects
      • 4.8.3. Bytes and Bytearray Operations
      • 4.8.4. Memory Views
    • 4.9. Set Types — set, frozenset
    • 4.10. Mapping Types — dict
      • 4.10.1. Dictionary view objects
    • 4.11. Context Manager Types
    • 4.12. Other Built-in Types
      • 4.12.1. Modules
      • 4.12.2. Classes and Class Instances
      • 4.12.3. Functions
      • 4.12.4. Methods
      • 4.12.5. Code Objects
      • 4.12.6. Type Objects
      • 4.12.7. The Null Object
      • 4.12.8. The Ellipsis Object
      • 4.12.9. The NotImplemented Object
      • 4.12.10. Boolean Values
      • 4.12.11. Internal Objects
    • 4.13. Special Attributes
  • 5. Built-in Exceptions
    • 5.1. Base classes
    • 5.2. Concrete exceptions
      • 5.2.1. OS exceptions
    • 5.3. Warnings
    • 5.4. Exception hierarchy
  • 6. Text Processing Services
    • 6.1. string — Common string operations
      • 6.1.1. String constants
      • 6.1.2. String Formatting
      • 6.1.3. Format String Syntax
        • 6.1.3.1. Format Specification Mini-Language
        • 6.1.3.2. Format examples
      • 6.1.4. Template strings
      • 6.1.5. Helper functions
    • 6.2. re — Regular expression operations
      • 6.2.1. Regular Expression Syntax
      • 6.2.2. Module Contents
      • 6.2.3. Regular Expression Objects
      • 6.2.4. Match Objects
      • 6.2.5. Regular Expression Examples
        • 6.2.5.1. Checking for a Pair
        • 6.2.5.2. Simulating scanf()
        • 6.2.5.3. search() vs. match()
        • 6.2.5.4. Making a Phonebook
        • 6.2.5.5. Text Munging
        • 6.2.5.6. Finding all Adverbs
        • 6.2.5.7. Finding all Adverbs and their Positions
        • 6.2.5.8. Raw String Notation
        • 6.2.5.9. Writing a Tokenizer
    • 6.3. difflib — Helpers for computing deltas
      • 6.3.1. SequenceMatcher Objects
      • 6.3.2. SequenceMatcher Examples
      • 6.3.3. Differ Objects
      • 6.3.4. Differ Example
      • 6.3.5. A command-line interface to difflib
    • 6.4. textwrap — Text wrapping and filling
    • 6.5. unicodedata — Unicode Database
    • 6.6. stringprep — Internet String Preparation
    • 6.7. readline — GNU readline interface
      • 6.7.1. Example
    • 6.8. rlcompleter — Completion function for GNU readline
      • 6.8.1. Completer Objects
  • 7. Binary Data Services
    • 7.1. struct — Interpret bytes as packed binary data
      • 7.1.1. Functions and Exceptions
      • 7.1.2. Format Strings
        • 7.1.2.1. Byte Order, Size, and Alignment
        • 7.1.2.2. Format Characters
        • 7.1.2.3. Examples
      • 7.1.3. Classes
    • 7.2. codecs — Codec registry and base classes
      • 7.2.1. Codec Base Classes
        • 7.2.1.1. Error Handlers
        • 7.2.1.2. Stateless Encoding and Decoding
        • 7.2.1.3. Incremental Encoding and Decoding
          • 7.2.1.3.1. IncrementalEncoder Objects
          • 7.2.1.3.2. IncrementalDecoder Objects
        • 7.2.1.4. Stream Encoding and Decoding
          • 7.2.1.4.1. StreamWriter Objects
          • 7.2.1.4.2. StreamReader Objects
          • 7.2.1.4.3. StreamReaderWriter Objects
          • 7.2.1.4.4. StreamRecoder Objects
      • 7.2.2. Encodings and Unicode
      • 7.2.3. Standard Encodings
      • 7.2.4. Python Specific Encodings
        • 7.2.4.1. Text Encodings
        • 7.2.4.2. Binary Transforms
        • 7.2.4.3. Text Transforms
      • 7.2.5. encodings.idna — Internationalized Domain Names in Applications
      • 7.2.6. encodings.mbcs — Windows ANSI codepage
      • 7.2.7. encodings.utf_8_sig — UTF-8 codec with BOM signature
  • 8. Data Types
    • 8.1. datetime — Basic date and time types
      • 8.1.1. Available Types
      • 8.1.2. timedelta Objects
      • 8.1.3. date Objects
      • 8.1.4. datetime Objects
      • 8.1.5. time Objects
      • 8.1.6. tzinfo Objects
      • 8.1.7. timezone Objects
      • 8.1.8. strftime() and strptime() Behavior
    • 8.2. calendar — General calendar-related functions
    • 8.3. collections — Container datatypes
      • 8.3.1. ChainMap objects
        • 8.3.1.1. ChainMap Examples and Recipes
      • 8.3.2. Counter objects
      • 8.3.3. deque objects
        • 8.3.3.1. deque Recipes
      • 8.3.4. defaultdict objects
        • 8.3.4.1. defaultdict Examples
      • 8.3.5. namedtuple() Factory Function for Tuples with Named Fields
      • 8.3.6. OrderedDict objects
        • 8.3.6.1. OrderedDict Examples and Recipes
      • 8.3.7. UserDict objects
      • 8.3.8. UserList objects
      • 8.3.9. UserString objects
    • 8.4. collections.abc — Abstract Base Classes for Containers
      • 8.4.1. Collections Abstract Base Classes
    • 8.5. heapq — Heap queue algorithm
      • 8.5.1. Basic Examples
      • 8.5.2. Priority Queue Implementation Notes
      • 8.5.3. Theory
    • 8.6. bisect — Array bisection algorithm
      • 8.6.1. Searching Sorted Lists
      • 8.6.2. Other Examples
    • 8.7. array — Efficient arrays of numeric values
    • 8.8. weakref — Weak references
      • 8.8.1. Weak Reference Objects
      • 8.8.2. Example
      • 8.8.3. Finalizer Objects
      • 8.8.4. Comparing finalizers with __del__() methods
    • 8.9. types — Dynamic type creation and names for built-in types
      • 8.9.1. Dynamic Type Creation
      • 8.9.2. Standard Interpreter Types
      • 8.9.3. Additional Utility Classes and Functions
    • 8.10. copy — Shallow and deep copy operations
    • 8.11. pprint — Data pretty printer
      • 8.11.1. PrettyPrinter Objects
      • 8.11.2. Example
    • 8.12. reprlib — Alternate repr() implementation
      • 8.12.1. Repr Objects
      • 8.12.2. Subclassing Repr Objects
    • 8.13. enum — Support for enumerations
      • 8.13.1. Module Contents
      • 8.13.2. Creating an Enum
      • 8.13.3. Programmatic access to enumeration members and their attributes
      • 8.13.4. Duplicating enum members and values
      • 8.13.5. Ensuring unique enumeration values
      • 8.13.6. Iteration
      • 8.13.7. Comparisons
      • 8.13.8. Allowed members and attributes of enumerations
      • 8.13.9. Restricted subclassing of enumerations
      • 8.13.10. Pickling
      • 8.13.11. Functional API
      • 8.13.12. Derived Enumerations
        • 8.13.12.1. IntEnum
        • 8.13.12.2. Others
      • 8.13.13. Interesting examples
        • 8.13.13.1. AutoNumber
        • 8.13.13.2. OrderedEnum
        • 8.13.13.3. DuplicateFreeEnum
        • 8.13.13.4. Planet
      • 8.13.14. How are Enums different?
        • 8.13.14.1. Enum Classes
        • 8.13.14.2. Enum Members (aka instances)
        • 8.13.14.3. Finer Points
  • 9. Numeric and Mathematical Modules
    • 9.1. numbers — Numeric abstract base classes
      • 9.1.1. The numeric tower
      • 9.1.2. Notes for type implementors
        • 9.1.2.1. Adding More Numeric ABCs
        • 9.1.2.2. Implementing the arithmetic operations
    • 9.2. math — Mathematical functions
      • 9.2.1. Number-theoretic and representation functions
      • 9.2.2. Power and logarithmic functions
      • 9.2.3. Trigonometric functions
      • 9.2.4. Angular conversion
      • 9.2.5. Hyperbolic functions
      • 9.2.6. Special functions
      • 9.2.7. Constants
    • 9.3. cmath — Mathematical functions for complex numbers
      • 9.3.1. Conversions to and from polar coordinates
      • 9.3.2. Power and logarithmic functions
      • 9.3.3. Trigonometric functions
      • 9.3.4. Hyperbolic functions
      • 9.3.5. Classification functions
      • 9.3.6. Constants
    • 9.4. decimal — Decimal fixed point and floating point arithmetic
      • 9.4.1. Quick-start Tutorial
      • 9.4.2. Decimal objects
        • 9.4.2.1. Logical operands
      • 9.4.3. Context objects
      • 9.4.4. Constants
      • 9.4.5. Rounding modes
      • 9.4.6. Signals
      • 9.4.7. Floating Point Notes
        • 9.4.7.1. Mitigating round-off error with increased precision
        • 9.4.7.2. Special values
      • 9.4.8. Working with threads
      • 9.4.9. Recipes
      • 9.4.10. Decimal FAQ
    • 9.5. fractions — Rational numbers
    • 9.6. random — Generate pseudo-random numbers
      • 9.6.1. Notes on Reproducibility
      • 9.6.2. Examples and Recipes
    • 9.7. statistics — Mathematical statistics functions
      • 9.7.1. Averages and measures of central location
      • 9.7.2. Measures of spread
      • 9.7.3. Function details
      • 9.7.4. Exceptions
  • 10. Functional Programming Modules
    • 10.1. itertools — Functions creating iterators for efficient looping
      • 10.1.1. Itertool functions
      • 10.1.2. Itertools Recipes
    • 10.2. functools — Higher-order functions and operations on callable objects
      • 10.2.1. partial Objects
    • 10.3. operator — Standard operators as functions
      • 10.3.1. Mapping Operators to Functions
      • 10.3.2. Inplace Operators
  • 11. File and Directory Access
    • 11.1. pathlib — Object-oriented filesystem paths
      • 11.1.1. Basic use
      • 11.1.2. Pure paths
        • 11.1.2.1. General properties
        • 11.1.2.2. Operators
        • 11.1.2.3. Accessing individual parts
        • 11.1.2.4. Methods and properties
      • 11.1.3. Concrete paths
        • 11.1.3.1. Methods
    • 11.2. os.path — Common pathname manipulations
    • 11.3. fileinput — Iterate over lines from multiple input streams
    • 11.4. stat — Interpreting stat() results
    • 11.5. filecmp — File and Directory Comparisons
      • 11.5.1. The dircmp class
    • 11.6. tempfile — Generate temporary files and directories
      • 11.6.1. Examples
    • 11.7. glob — Unix style pathname pattern expansion
    • 11.8. fnmatch — Unix filename pattern matching
    • 11.9. linecache — Random access to text lines
    • 11.10. shutil — High-level file operations
      • 11.10.1. Directory and files operations
        • 11.10.1.1. copytree example
      • 11.10.2. Archiving operations
        • 11.10.2.1. Archiving example
      • 11.10.3. Querying the size of the output terminal
    • 11.11. macpath — Mac OS 9 path manipulation functions
  • 12. Data Persistence
    • 12.1. pickle — Python object serialization
      • 12.1.1. Relationship to other Python modules
        • 12.1.1.1. Comparison with marshal
        • 12.1.1.2. Comparison with json
      • 12.1.2. Data stream format
      • 12.1.3. Module Interface
      • 12.1.4. What can be pickled and unpickled?
      • 12.1.5. Pickling Class Instances
        • 12.1.5.1. Persistence of External Objects
        • 12.1.5.2. Dispatch Tables
        • 12.1.5.3. Handling Stateful Objects
      • 12.1.6. Restricting Globals
      • 12.1.7. Performance
      • 12.1.8. Examples
    • 12.2. copyreg — Register pickle support functions
      • 12.2.1. Example
    • 12.3. shelve — Python object persistence
      • 12.3.1. Restrictions
      • 12.3.2. Example
    • 12.4. marshal — Internal Python object serialization
    • 12.5. dbm — Interfaces to Unix “databases”
      • 12.5.1. dbm.gnu — GNU’s reinterpretation of dbm
      • 12.5.2. dbm.ndbm — Interface based on ndbm
      • 12.5.3. dbm.dumb — Portable DBM implementation
    • 12.6. sqlite3 — DB-API 2.0 interface for SQLite databases
      • 12.6.1. Module functions and constants
      • 12.6.2. Connection Objects
      • 12.6.3. Cursor Objects
      • 12.6.4. Row Objects
      • 12.6.5. SQLite and Python types
        • 12.6.5.1. Introduction
        • 12.6.5.2. Using adapters to store additional Python types in SQLite databases
          • 12.6.5.2.1. Letting your object adapt itself
          • 12.6.5.2.2. Registering an adapter callable
        • 12.6.5.3. Converting SQLite values to custom Python types
        • 12.6.5.4. Default adapters and converters
      • 12.6.6. Controlling Transactions
      • 12.6.7. Using sqlite3 efficiently
        • 12.6.7.1. Using shortcut methods
        • 12.6.7.2. Accessing columns by name instead of by index
        • 12.6.7.3. Using the connection as a context manager
      • 12.6.8. Common issues
        • 12.6.8.1. Multithreading
  • 13. Data Compression and Archiving
    • 13.1. zlib — Compression compatible with gzip
    • 13.2. gzip — Support for gzip files
      • 13.2.1. Examples of usage
    • 13.3. bz2 — Support for bzip2 compression
      • 13.3.1. (De)compression of files
      • 13.3.2. Incremental (de)compression
      • 13.3.3. One-shot (de)compression
    • 13.4. lzma — Compression using the LZMA algorithm
      • 13.4.1. Reading and writing compressed files
      • 13.4.2. Compressing and decompressing data in memory
      • 13.4.3. Miscellaneous
      • 13.4.4. Specifying custom filter chains
      • 13.4.5. Examples
    • 13.5. zipfile — Work with ZIP archives
      • 13.5.1. ZipFile Objects
      • 13.5.2. PyZipFile Objects
      • 13.5.3. ZipInfo Objects
    • 13.6. tarfile — Read and write tar archive files
      • 13.6.1. TarFile Objects
      • 13.6.2. TarInfo Objects
      • 13.6.3. Command Line Interface
        • 13.6.3.1. Command line options
      • 13.6.4. Examples
      • 13.6.5. Supported tar formats
      • 13.6.6. Unicode issues
  • 14. File Formats
    • 14.1. csv — CSV File Reading and Writing
      • 14.1.1. Module Contents
      • 14.1.2. Dialects and Formatting Parameters
      • 14.1.3. Reader Objects
      • 14.1.4. Writer Objects
      • 14.1.5. Examples
    • 14.2. configparser — Configuration file parser
      • 14.2.1. Quick Start
      • 14.2.2. Supported Datatypes
      • 14.2.3. Fallback Values
      • 14.2.4. Supported INI File Structure
      • 14.2.5. Interpolation of values
      • 14.2.6. Mapping Protocol Access
      • 14.2.7. Customizing Parser Behaviour
      • 14.2.8. Legacy API Examples
      • 14.2.9. ConfigParser Objects
      • 14.2.10. RawConfigParser Objects
      • 14.2.11. Exceptions
    • 14.3. netrc — netrc file processing
      • 14.3.1. netrc Objects
    • 14.4. xdrlib — Encode and decode XDR data
      • 14.4.1. Packer Objects
      • 14.4.2. Unpacker Objects
      • 14.4.3. Exceptions
    • 14.5. plistlib — Generate and parse Mac OS X .plist files
      • 14.5.1. Examples
  • 15. Cryptographic Services
    • 15.1. hashlib — Secure hashes and message digests
      • 15.1.1. Hash algorithms
      • 15.1.2. Key Derivation Function
    • 15.2. hmac — Keyed-Hashing for Message Authentication
  • 16. Generic Operating System Services
    • 16.1. os — Miscellaneous operating system interfaces
      • 16.1.1. File Names, Command Line Arguments, and Environment Variables
      • 16.1.2. Process Parameters
      • 16.1.3. File Object Creation
      • 16.1.4. File Descriptor Operations
        • 16.1.4.1. Querying the size of a terminal
        • 16.1.4.2. Inheritance of File Descriptors
      • 16.1.5. Files and Directories
        • 16.1.5.1. Linux extended attributes
      • 16.1.6. Process Management
      • 16.1.7. Interface to the scheduler
      • 16.1.8. Miscellaneous System Information
      • 16.1.9. Miscellaneous Functions
    • 16.2. io — Core tools for working with streams
      • 16.2.1. Overview
        • 16.2.1.1. Text I/O
        • 16.2.1.2. Binary I/O
        • 16.2.1.3. Raw I/O
      • 16.2.2. High-level Module Interface
        • 16.2.2.1. In-memory streams
      • 16.2.3. Class hierarchy
        • 16.2.3.1. I/O Base Classes
        • 16.2.3.2. Raw File I/O
        • 16.2.3.3. Buffered Streams
        • 16.2.3.4. Text I/O
      • 16.2.4. Performance
        • 16.2.4.1. Binary I/O
        • 16.2.4.2. Text I/O
        • 16.2.4.3. Multi-threading
        • 16.2.4.4. Reentrancy
    • 16.3. time — Time access and conversions
    • 16.4. argparse — Parser for command-line options, arguments and sub-commands
      • 16.4.1. Example
        • 16.4.1.1. Creating a parser
        • 16.4.1.2. Adding arguments
        • 16.4.1.3. Parsing arguments
      • 16.4.2. ArgumentParser objects
        • 16.4.2.1. prog
        • 16.4.2.2. usage
        • 16.4.2.3. description
        • 16.4.2.4. epilog
        • 16.4.2.5. parents
        • 16.4.2.6. formatter_class
        • 16.4.2.7. prefix_chars
        • 16.4.2.8. fromfile_prefix_chars
        • 16.4.2.9. argument_default
        • 16.4.2.10. conflict_handler
        • 16.4.2.11. add_help
      • 16.4.3. The add_argument() method
        • 16.4.3.1. name or flags
        • 16.4.3.2. action
        • 16.4.3.3. nargs
        • 16.4.3.4. const
        • 16.4.3.5. default
        • 16.4.3.6. type
        • 16.4.3.7. choices
        • 16.4.3.8. required
        • 16.4.3.9. help
        • 16.4.3.10. metavar
        • 16.4.3.11. dest
        • 16.4.3.12. Action classes
      • 16.4.4. The parse_args() method
        • 16.4.4.1. Option value syntax
        • 16.4.4.2. Invalid arguments
        • 16.4.4.3. Arguments containing -
        • 16.4.4.4. Argument abbreviations (prefix matching)
        • 16.4.4.5. Beyond sys.argv
        • 16.4.4.6. The Namespace object
      • 16.4.5. Other utilities
        • 16.4.5.1. Sub-commands
        • 16.4.5.2. FileType objects
        • 16.4.5.3. Argument groups
        • 16.4.5.4. Mutual exclusion
        • 16.4.5.5. Parser defaults
        • 16.4.5.6. Printing help
        • 16.4.5.7. Partial parsing
        • 16.4.5.8. Customizing file parsing
        • 16.4.5.9. Exiting methods
      • 16.4.6. Upgrading optparse code
    • 16.5. getopt — C-style parser for command line options
    • 16.6. logging — Logging facility for Python
      • 16.6.1. Logger Objects
      • 16.6.2. Logging Levels
      • 16.6.3. Handler Objects
      • 16.6.4. Formatter Objects
      • 16.6.5. Filter Objects
      • 16.6.6. LogRecord Objects
      • 16.6.7. LogRecord attributes
      • 16.6.8. LoggerAdapter Objects
      • 16.6.9. Thread Safety
      • 16.6.10. Module-Level Functions
      • 16.6.11. Module-Level Attributes
      • 16.6.12. Integration with the warnings module
    • 16.7. logging.config — Logging configuration
      • 16.7.1. Configuration functions
      • 16.7.2. Configuration dictionary schema
        • 16.7.2.1. Dictionary Schema Details
        • 16.7.2.2. Incremental Configuration
        • 16.7.2.3. Object connections
        • 16.7.2.4. User-defined objects
        • 16.7.2.5. Access to external objects
        • 16.7.2.6. Access to internal objects
        • 16.7.2.7. Import resolution and custom importers
      • 16.7.3. Configuration file format
    • 16.8. logging.handlers — Logging handlers
      • 16.8.1. StreamHandler
      • 16.8.2. FileHandler
      • 16.8.3. NullHandler
      • 16.8.4. WatchedFileHandler
      • 16.8.5. BaseRotatingHandler
      • 16.8.6. RotatingFileHandler
      • 16.8.7. TimedRotatingFileHandler
      • 16.8.8. SocketHandler
      • 16.8.9. DatagramHandler
      • 16.8.10. SysLogHandler
      • 16.8.11. NTEventLogHandler
      • 16.8.12. SMTPHandler
      • 16.8.13. MemoryHandler
      • 16.8.14. HTTPHandler
      • 16.8.15. QueueHandler
      • 16.8.16. QueueListener
    • 16.9. getpass — Portable password input
    • 16.10. curses — Terminal handling for character-cell displays
      • 16.10.1. Functions
      • 16.10.2. Window Objects
      • 16.10.3. Constants
    • 16.11. curses.textpad — Text input widget for curses programs
      • 16.11.1. Textbox objects
    • 16.12. curses.ascii — Utilities for ASCII characters
    • 16.13. curses.panel — A panel stack extension for curses
      • 16.13.1. Functions
      • 16.13.2. Panel Objects
    • 16.14. platform — Access to underlying platform’s identifying data
      • 16.14.1. Cross Platform
      • 16.14.2. Java Platform
      • 16.14.3. Windows Platform
        • 16.14.3.1. Win95/98 specific
      • 16.14.4. Mac OS Platform
      • 16.14.5. Unix Platforms
    • 16.15. errno — Standard errno system symbols
    • 16.16. ctypes — A foreign function library for Python
      • 16.16.1. ctypes tutorial
        • 16.16.1.1. Loading dynamic link libraries
        • 16.16.1.2. Accessing functions from loaded dlls
        • 16.16.1.3. Calling functions
        • 16.16.1.4. Fundamental data types
        • 16.16.1.5. Calling functions, continued
        • 16.16.1.6. Calling functions with your own custom data types
        • 16.16.1.7. Specifying the required argument types (function prototypes)
        • 16.16.1.8. Return types
        • 16.16.1.9. Passing pointers (or: passing parameters by reference)
        • 16.16.1.10. Structures and unions
        • 16.16.1.11. Structure/union alignment and byte order
        • 16.16.1.12. Bit fields in structures and unions
        • 16.16.1.13. Arrays
        • 16.16.1.14. Pointers
        • 16.16.1.15. Type conversions
        • 16.16.1.16. Incomplete Types
        • 16.16.1.17. Callback functions
        • 16.16.1.18. Accessing values exported from dlls
        • 16.16.1.19. Surprises
        • 16.16.1.20. Variable-sized data types
      • 16.16.2. ctypes reference
        • 16.16.2.1. Finding shared libraries
        • 16.16.2.2. Loading shared libraries
        • 16.16.2.3. Foreign functions
        • 16.16.2.4. Function prototypes
        • 16.16.2.5. Utility functions
        • 16.16.2.6. Data types
        • 16.16.2.7. Fundamental data types
        • 16.16.2.8. Structured data types
        • 16.16.2.9. Arrays and pointers
  • 17. Concurrent Execution
    • 17.1. threading — Thread-based parallelism
      • 17.1.1. Thread-Local Data
      • 17.1.2. Thread Objects
      • 17.1.3. Lock Objects
      • 17.1.4. RLock Objects
      • 17.1.5. Condition Objects
      • 17.1.6. Semaphore Objects
        • 17.1.6.1. Semaphore Example
      • 17.1.7. Event Objects
      • 17.1.8. Timer Objects
      • 17.1.9. Barrier Objects
      • 17.1.10. Using locks, conditions, and semaphores in the with statement
    • 17.2. multiprocessing — Process-based parallelism
      • 17.2.1. Introduction
        • 17.2.1.1. The Process class
        • 17.2.1.2. Contexts and start methods
        • 17.2.1.3. Exchanging objects between processes
        • 17.2.1.4. Synchronization between processes
        • 17.2.1.5. Sharing state between processes
        • 17.2.1.6. Using a pool of workers
      • 17.2.2. Reference
        • 17.2.2.1. Process and exceptions
        • 17.2.2.2. Pipes and Queues
        • 17.2.2.3. Miscellaneous
        • 17.2.2.4. Connection Objects
        • 17.2.2.5. Synchronization primitives
        • 17.2.2.6. Shared ctypes Objects
          • 17.2.2.6.1. The multiprocessing.sharedctypes module
        • 17.2.2.7. Managers
          • 17.2.2.7.1. Namespace objects
          • 17.2.2.7.2. Customized managers
          • 17.2.2.7.3. Using a remote manager
        • 17.2.2.8. Proxy Objects
          • 17.2.2.8.1. Cleanup
        • 17.2.2.9. Process Pools
        • 17.2.2.10. Listeners and Clients
          • 17.2.2.10.1. Address Formats
        • 17.2.2.11. Authentication keys
        • 17.2.2.12. Logging
        • 17.2.2.13. The multiprocessing.dummy module
      • 17.2.3. Programming guidelines
        • 17.2.3.1. All start methods
        • 17.2.3.2. The spawn and forkserver start methods
      • 17.2.4. Examples
    • 17.3. The concurrent package
    • 17.4. concurrent.futures — Launching parallel tasks
      • 17.4.1. Executor Objects
      • 17.4.2. ThreadPoolExecutor
        • 17.4.2.1. ThreadPoolExecutor Example
      • 17.4.3. ProcessPoolExecutor
        • 17.4.3.1. ProcessPoolExecutor Example
      • 17.4.4. Future Objects
      • 17.4.5. Module Functions
      • 17.4.6. Exception classes
    • 17.5. subprocess — Subprocess management
      • 17.5.1. Using the subprocess Module
        • 17.5.1.1. Frequently Used Arguments
        • 17.5.1.2. Popen Constructor
        • 17.5.1.3. Exceptions
      • 17.5.2. Security Considerations
      • 17.5.3. Popen Objects
      • 17.5.4. Windows Popen Helpers
        • 17.5.4.1. Constants
      • 17.5.5. Replacing Older Functions with the subprocess Module
        • 17.5.5.1. Replacing /bin/sh shell backquote
        • 17.5.5.2. Replacing shell pipeline
        • 17.5.5.3. Replacing os.system()
        • 17.5.5.4. Replacing the os.spawn family
        • 17.5.5.5. Replacing os.popen(), os.popen2(), os.popen3()
        • 17.5.5.6. Replacing functions from the popen2 module
      • 17.5.6. Legacy Shell Invocation Functions
      • 17.5.7. Notes
        • 17.5.7.1. Converting an argument sequence to a string on Windows
    • 17.6. sched — Event scheduler
      • 17.6.1. Scheduler Objects
    • 17.7. queue — A synchronized queue class
      • 17.7.1. Queue Objects
    • 17.8. dummy_threading — Drop-in replacement for the threading module
    • 17.9. _thread — Low-level threading API
    • 17.10. _dummy_thread — Drop-in replacement for the _thread module
  • 18. Interprocess Communication and Networking
    • 18.1. socket — Low-level networking interface
      • 18.1.1. Socket families
      • 18.1.2. Module contents
        • 18.1.2.1. Exceptions
        • 18.1.2.2. Constants
        • 18.1.2.3. Functions
          • 18.1.2.3.1. Creating sockets
          • 18.1.2.3.2. Other functions
      • 18.1.3. Socket Objects
      • 18.1.4. Notes on socket timeouts
        • 18.1.4.1. Timeouts and the connect method
        • 18.1.4.2. Timeouts and the accept method
      • 18.1.5. Example
    • 18.2. ssl — TLS/SSL wrapper for socket objects
      • 18.2.1. Functions, Constants, and Exceptions
        • 18.2.1.1. Socket creation
        • 18.2.1.2. Context creation
        • 18.2.1.3. Random generation
        • 18.2.1.4. Certificate handling
        • 18.2.1.5. Constants
      • 18.2.2. SSL Sockets
      • 18.2.3. SSL Contexts
      • 18.2.4. Certificates
        • 18.2.4.1. Certificate chains
        • 18.2.4.2. CA certificates
        • 18.2.4.3. Combined key and certificate
        • 18.2.4.4. Self-signed certificates
      • 18.2.5. Examples
        • 18.2.5.1. Testing for SSL support
        • 18.2.5.2. Client-side operation
        • 18.2.5.3. Server-side operation
      • 18.2.6. Notes on non-blocking sockets
      • 18.2.7. Security considerations
        • 18.2.7.1. Best defaults
        • 18.2.7.2. Manual settings
          • 18.2.7.2.1. Verifying certificates
          • 18.2.7.2.2. Protocol versions
          • 18.2.7.2.3. Cipher selection
        • 18.2.7.3. Multi-processing
    • 18.3. select — Waiting for I/O completion
      • 18.3.1. /dev/poll Polling Objects
      • 18.3.2. Edge and Level Trigger Polling (epoll) Objects
      • 18.3.3. Polling Objects
      • 18.3.4. Kqueue Objects
      • 18.3.5. Kevent Objects
    • 18.4. selectors – High-level I/O multiplexing
      • 18.4.1. Introduction
      • 18.4.2. Classes
      • 18.4.3. Examples
    • 18.5. asyncio – Asynchronous I/O, event loop, coroutines and tasks
      • 18.5.1. Base Event Loop
        • 18.5.1.1. Run an event loop
        • 18.5.1.2. Calls
        • 18.5.1.3. Delayed calls
        • 18.5.1.4. Tasks
        • 18.5.1.5. Creating connections
        • 18.5.1.6. Creating listening connections
        • 18.5.1.7. Watch file descriptors
        • 18.5.1.8. Low-level socket operations
        • 18.5.1.9. Resolve host name
        • 18.5.1.10. Connect pipes
        • 18.5.1.11. UNIX signals
        • 18.5.1.12. Executor
        • 18.5.1.13. Error Handling API
        • 18.5.1.14. Debug mode
        • 18.5.1.15. Server
        • 18.5.1.16. Handle
        • 18.5.1.17. Event loop examples
          • 18.5.1.17.1. Hello World with call_soon()
          • 18.5.1.17.2. Display the current date with call_later()
          • 18.5.1.17.3. Watch a file descriptor for read events
          • 18.5.1.17.4. Set signal handlers for SIGINT and SIGTERM
      • 18.5.2. Event loops
        • 18.5.2.1. Event loop functions
        • 18.5.2.2. Available event loops
        • 18.5.2.3. Platform support
          • 18.5.2.3.1. Windows
          • 18.5.2.3.2. Mac OS X
        • 18.5.2.4. Event loop policies and the default policy
        • 18.5.2.5. Event loop policy interface
        • 18.5.2.6. Access to the global loop policy
      • 18.5.3. Tasks and coroutines
        • 18.5.3.1. Coroutines
          • 18.5.3.1.1. Example: Hello World coroutine
          • 18.5.3.1.2. Example: Coroutine displaying the current date
          • 18.5.3.1.3. Example: Chain coroutines
        • 18.5.3.2. InvalidStateError
        • 18.5.3.3. TimeoutError
        • 18.5.3.4. Future
          • 18.5.3.4.1. Example: Future with run_until_complete()
          • 18.5.3.4.2. Example: Future with run_forever()
        • 18.5.3.5. Task
          • 18.5.3.5.1. Example: Parallel execution of tasks
        • 18.5.3.6. Task functions
      • 18.5.4. Transports and protocols (low-level API)
        • 18.5.4.1. Transports
          • 18.5.4.1.1. BaseTransport
          • 18.5.4.1.2. ReadTransport
          • 18.5.4.1.3. WriteTransport
          • 18.5.4.1.4. DatagramTransport
          • 18.5.4.1.5. BaseSubprocessTransport
        • 18.5.4.2. Protocols
          • 18.5.4.2.1. Protocol classes
          • 18.5.4.2.2. Connection callbacks
          • 18.5.4.2.3. Streaming protocols
          • 18.5.4.2.4. Datagram protocols
          • 18.5.4.2.5. Flow control callbacks
          • 18.5.4.2.6. Coroutines and protocols
        • 18.5.4.3. Protocol examples
          • 18.5.4.3.1. TCP echo client protocol
          • 18.5.4.3.2. TCP echo server protocol
          • 18.5.4.3.3. UDP echo client protocol
          • 18.5.4.3.4. UDP echo server protocol
          • 18.5.4.3.5. Register an open socket to wait for data using a protocol
      • 18.5.5. Streams (high-level API)
        • 18.5.5.1. Stream functions
        • 18.5.5.2. StreamReader
        • 18.5.5.3. StreamWriter
        • 18.5.5.4. StreamReaderProtocol
        • 18.5.5.5. IncompleteReadError
        • 18.5.5.6. Stream examples
          • 18.5.5.6.1. TCP echo client using streams
          • 18.5.5.6.2. TCP echo server using streams
          • 18.5.5.6.3. Get HTTP headers
          • 18.5.5.6.4. Register an open socket to wait for data using streams
      • 18.5.6. Subprocess
        • 18.5.6.1. Windows event loop
        • 18.5.6.2. Create a subprocess: high-level API using Process
        • 18.5.6.3. Create a subprocess: low-level API using subprocess.Popen
        • 18.5.6.4. Constants
        • 18.5.6.5. Process
      • 18.5.7. Subprocess and threads
      • 18.5.8. Subprocess examples
        • 18.5.8.1. Subprocess using transport and protocol
        • 18.5.8.2. Subprocess using streams
      • 18.5.9. Synchronization primitives
        • 18.5.9.1. Locks
          • 18.5.9.1.1. Lock
          • 18.5.9.1.2. Event
          • 18.5.9.1.3. Condition
        • 18.5.9.2. Semaphores
          • 18.5.9.2.1. Semaphore
          • 18.5.9.2.2. BoundedSemaphore
      • 18.5.10. Queues
        • 18.5.10.1. Queue
        • 18.5.10.2. PriorityQueue
        • 18.5.10.3. LifoQueue
          • 18.5.10.3.1. JoinableQueue
          • 18.5.10.3.2. Exceptions
      • 18.5.11. Develop with asyncio
        • 18.5.11.1. Debug mode of asyncio
        • 18.5.11.2. Cancellation
        • 18.5.11.3. Concurrency and multithreading
        • 18.5.11.4. Handle blocking functions correctly
        • 18.5.11.5. Logging
        • 18.5.11.6. Detect coroutine objects never scheduled
        • 18.5.11.7. Detect exceptions never consumed
        • 18.5.11.8. Chain coroutines correctly
        • 18.5.11.9. Pending task destroyed
        • 18.5.11.10. Close transports and event loops
    • 18.6. asyncore — Asynchronous socket handler
      • 18.6.1. asyncore Example basic HTTP client
      • 18.6.2. asyncore Example basic echo server
    • 18.7. asynchat — Asynchronous socket command/response handler
      • 18.7.1. asynchat - Auxiliary Classes
      • 18.7.2. asynchat Example
    • 18.8. signal — Set handlers for asynchronous events
      • 18.8.1. General rules
        • 18.8.1.1. Execution of Python signal handlers
        • 18.8.1.2. Signals and threads
      • 18.8.2. Module contents
      • 18.8.3. Example
    • 18.9. mmap — Memory-mapped file support
  • 19. Internet Data Handling
    • 19.1. email — An email and MIME handling package
      • 19.1.1. email.message: Representing an email message
      • 19.1.2. email.parser: Parsing email messages
        • 19.1.2.1. FeedParser API
        • 19.1.2.2. Parser class API
        • 19.1.2.3. Additional notes
      • 19.1.3. email.generator: Generating MIME documents
      • 19.1.4. email.policy: Policy Objects
      • 19.1.5. email.headerregistry: Custom Header Objects
      • 19.1.6. email.contentmanager: Managing MIME Content
        • 19.1.6.1. Content Manager Instances
      • 19.1.7. email.mime: Creating email and MIME objects from scratch
      • 19.1.8. email.header: Internationalized headers
      • 19.1.9. email.charset: Representing character sets
      • 19.1.10. email.encoders: Encoders
      • 19.1.11. email.errors: Exception and Defect classes
      • 19.1.12. email.utils: Miscellaneous utilities
      • 19.1.13. email.iterators: Iterators
      • 19.1.14. email: Examples
        • 19.1.14.1. Examples using the Provisional API
      • 19.1.15. Package History
      • 19.1.16. Differences from mimelib
    • 19.2. json — JSON encoder and decoder
      • 19.2.1. Basic Usage
      • 19.2.2. Encoders and Decoders
      • 19.2.3. Standard Compliance and Interoperability
        • 19.2.3.1. Character Encodings
        • 19.2.3.2. Infinite and NaN Number Values
        • 19.2.3.3. Repeated Names Within an Object
        • 19.2.3.4. Top-level Non-Object, Non-Array Values
        • 19.2.3.5. Implementation Limitations
    • 19.3. mailcap — Mailcap file handling
    • 19.4. mailbox — Manipulate mailboxes in various formats
      • 19.4.1. Mailbox objects
        • 19.4.1.1. Maildir
        • 19.4.1.2. mbox
        • 19.4.1.3. MH
        • 19.4.1.4. Babyl
        • 19.4.1.5. MMDF
      • 19.4.2. Message objects
        • 19.4.2.1. MaildirMessage
        • 19.4.2.2. mboxMessage
        • 19.4.2.3. MHMessage
        • 19.4.2.4. BabylMessage
        • 19.4.2.5. MMDFMessage
      • 19.4.3. Exceptions
      • 19.4.4. Examples
    • 19.5. mimetypes — Map filenames to MIME types
      • 19.5.1. MimeTypes Objects
    • 19.6. base64 — Base16, Base32, Base64, Base85 Data Encodings
    • 19.7. binhex — Encode and decode binhex4 files
      • 19.7.1. Notes
    • 19.8. binascii — Convert between binary and ASCII
    • 19.9. quopri — Encode and decode MIME quoted-printable data
    • 19.10. uu — Encode and decode uuencode files
  • 20. Structured Markup Processing Tools
    • 20.1. html — HyperText Markup Language support
    • 20.2. html.parser — Simple HTML and XHTML parser
      • 20.2.1. Example HTML Parser Application
      • 20.2.2. HTMLParser Methods
      • 20.2.3. Examples
    • 20.3. html.entities — Definitions of HTML general entities
    • 20.4. XML Processing Modules
      • 20.4.1. XML vulnerabilities
      • 20.4.2. The defusedxml and defusedexpat Packages
    • 20.5. xml.etree.ElementTree — The ElementTree XML API
      • 20.5.1. Tutorial
        • 20.5.1.1. XML tree and elements
        • 20.5.1.2. Parsing XML
        • 20.5.1.3. Pull API for non-blocking parsing
        • 20.5.1.4. Finding interesting elements
        • 20.5.1.5. Modifying an XML File
        • 20.5.1.6. Building XML documents
        • 20.5.1.7. Parsing XML with Namespaces
        • 20.5.1.8. Additional resources
      • 20.5.2. XPath support
        • 20.5.2.1. Example
        • 20.5.2.2. Supported XPath syntax
      • 20.5.3. Reference
        • 20.5.3.1. Functions
        • 20.5.3.2. Element Objects
        • 20.5.3.3. ElementTree Objects
        • 20.5.3.4. QName Objects
        • 20.5.3.5. TreeBuilder Objects
        • 20.5.3.6. XMLParser Objects
        • 20.5.3.7. XMLPullParser Objects
        • 20.5.3.8. Exceptions
    • 20.6. xml.dom — The Document Object Model API
      • 20.6.1. Module Contents
      • 20.6.2. Objects in the DOM
        • 20.6.2.1. DOMImplementation Objects
        • 20.6.2.2. Node Objects
        • 20.6.2.3. NodeList Objects
        • 20.6.2.4. DocumentType Objects
        • 20.6.2.5. Document Objects
        • 20.6.2.6. Element Objects
        • 20.6.2.7. Attr Objects
        • 20.6.2.8. NamedNodeMap Objects
        • 20.6.2.9. Comment Objects
        • 20.6.2.10. Text and CDATASection Objects
        • 20.6.2.11. ProcessingInstruction Objects
        • 20.6.2.12. Exceptions
      • 20.6.3. Conformance
        • 20.6.3.1. Type Mapping
        • 20.6.3.2. Accessor Methods
    • 20.7. xml.dom.minidom — Minimal DOM implementation
      • 20.7.1. DOM Objects
      • 20.7.2. DOM Example
      • 20.7.3. minidom and the DOM standard
    • 20.8. xml.dom.pulldom — Support for building partial DOM trees
      • 20.8.1. DOMEventStream Objects
    • 20.9. xml.sax — Support for SAX2 parsers
      • 20.9.1. SAXException Objects
    • 20.10. xml.sax.handler — Base classes for SAX handlers
      • 20.10.1. ContentHandler Objects
      • 20.10.2. DTDHandler Objects
      • 20.10.3. EntityResolver Objects
      • 20.10.4. ErrorHandler Objects
    • 20.11. xml.sax.saxutils — SAX Utilities
    • 20.12. xml.sax.xmlreader — Interface for XML parsers
      • 20.12.1. XMLReader Objects
      • 20.12.2. IncrementalParser Objects
      • 20.12.3. Locator Objects
      • 20.12.4. InputSource Objects
      • 20.12.5. The Attributes Interface
      • 20.12.6. The AttributesNS Interface
    • 20.13. xml.parsers.expat — Fast XML parsing using Expat
      • 20.13.1. XMLParser Objects
      • 20.13.2. ExpatError Exceptions
      • 20.13.3. Example
      • 20.13.4. Content Model Descriptions
      • 20.13.5. Expat error constants
  • 21. Internet Protocols and Support
    • 21.1. webbrowser — Convenient Web-browser controller
      • 21.1.1. Browser Controller Objects
    • 21.2. cgi — Common Gateway Interface support
      • 21.2.1. Introduction
      • 21.2.2. Using the cgi module
      • 21.2.3. Higher Level Interface
      • 21.2.4. Functions
      • 21.2.5. Caring about security
      • 21.2.6. Installing your CGI script on a Unix system
      • 21.2.7. Testing your CGI script
      • 21.2.8. Debugging CGI scripts
      • 21.2.9. Common problems and solutions
    • 21.3. cgitb — Traceback manager for CGI scripts
    • 21.4. wsgiref — WSGI Utilities and Reference Implementation
      • 21.4.1. wsgiref.util – WSGI environment utilities
      • 21.4.2. wsgiref.headers – WSGI response header tools
      • 21.4.3. wsgiref.simple_server – a simple WSGI HTTP server
      • 21.4.4. wsgiref.validate — WSGI conformance checker
      • 21.4.5. wsgiref.handlers – server/gateway base classes
      • 21.4.6. Examples
    • 21.5. urllib — URL handling modules
    • 21.6. urllib.request — Extensible library for opening URLs
      • 21.6.1. Request Objects
      • 21.6.2. OpenerDirector Objects
      • 21.6.3. BaseHandler Objects
      • 21.6.4. HTTPRedirectHandler Objects
      • 21.6.5. HTTPCookieProcessor Objects
      • 21.6.6. ProxyHandler Objects
      • 21.6.7. HTTPPasswordMgr Objects
      • 21.6.8. AbstractBasicAuthHandler Objects
      • 21.6.9. HTTPBasicAuthHandler Objects
      • 21.6.10. ProxyBasicAuthHandler Objects
      • 21.6.11. AbstractDigestAuthHandler Objects
      • 21.6.12. HTTPDigestAuthHandler Objects
      • 21.6.13. ProxyDigestAuthHandler Objects
      • 21.6.14. HTTPHandler Objects
      • 21.6.15. HTTPSHandler Objects
      • 21.6.16. FileHandler Objects
      • 21.6.17. DataHandler Objects
      • 21.6.18. FTPHandler Objects
      • 21.6.19. CacheFTPHandler Objects
      • 21.6.20. UnknownHandler Objects
      • 21.6.21. HTTPErrorProcessor Objects
      • 21.6.22. Examples
      • 21.6.23. Legacy interface
      • 21.6.24. urllib.request Restrictions
    • 21.7. urllib.response — Response classes used by urllib
    • 21.8. urllib.parse — Parse URLs into components
      • 21.8.1. URL Parsing
      • 21.8.2. Parsing ASCII Encoded Bytes
      • 21.8.3. Structured Parse Results
      • 21.8.4. URL Quoting
    • 21.9. urllib.error — Exception classes raised by urllib.request
    • 21.10. urllib.robotparser — Parser for robots.txt
    • 21.11. http — HTTP modules
    • 21.12. http.client — HTTP protocol client
      • 21.12.1. HTTPConnection Objects
      • 21.12.2. HTTPResponse Objects
      • 21.12.3. Examples
      • 21.12.4. HTTPMessage Objects
    • 21.13. ftplib — FTP protocol client
      • 21.13.1. FTP Objects
      • 21.13.2. FTP_TLS Objects
    • 21.14. poplib — POP3 protocol client
      • 21.14.1. POP3 Objects
      • 21.14.2. POP3 Example
    • 21.15. imaplib — IMAP4 protocol client
      • 21.15.1. IMAP4 Objects
      • 21.15.2. IMAP4 Example
    • 21.16. nntplib — NNTP protocol client
      • 21.16.1. NNTP Objects
        • 21.16.1.1. Attributes
        • 21.16.1.2. Methods
      • 21.16.2. Utility functions
    • 21.17. smtplib — SMTP protocol client
      • 21.17.1. SMTP Objects
      • 21.17.2. SMTP Example
    • 21.18. smtpd — SMTP Server
      • 21.18.1. SMTPServer Objects
      • 21.18.2. DebuggingServer Objects
      • 21.18.3. PureProxy Objects
      • 21.18.4. MailmanProxy Objects
      • 21.18.5. SMTPChannel Objects
    • 21.19. telnetlib — Telnet client
      • 21.19.1. Telnet Objects
      • 21.19.2. Telnet Example
    • 21.20. uuid — UUID objects according to RFC 4122
      • 21.20.1. Example
    • 21.21. socketserver — A framework for network servers
      • 21.21.1. Server Creation Notes
      • 21.21.2. Server Objects
      • 21.21.3. RequestHandler Objects
      • 21.21.4. Examples
        • 21.21.4.1. socketserver.TCPServer Example
        • 21.21.4.2. socketserver.UDPServer Example
        • 21.21.4.3. Asynchronous Mixins
    • 21.22. http.server — HTTP servers
    • 21.23. http.cookies — HTTP state management
      • 21.23.1. Cookie Objects
      • 21.23.2. Morsel Objects
      • 21.23.3. Example
    • 21.24. http.cookiejar — Cookie handling for HTTP clients
      • 21.24.1. CookieJar and FileCookieJar Objects
      • 21.24.2. FileCookieJar subclasses and co-operation with web browsers
      • 21.24.3. CookiePolicy Objects
      • 21.24.4. DefaultCookiePolicy Objects
      • 21.24.5. Cookie Objects
      • 21.24.6. Examples
    • 21.25. xmlrpc — XMLRPC server and client modules
    • 21.26. xmlrpc.client — XML-RPC client access
      • 21.26.1. ServerProxy Objects
      • 21.26.2. DateTime Objects
      • 21.26.3. Binary Objects
      • 21.26.4. Fault Objects
      • 21.26.5. ProtocolError Objects
      • 21.26.6. MultiCall Objects
      • 21.26.7. Convenience Functions
      • 21.26.8. Example of Client Usage
      • 21.26.9. Example of Client and Server Usage
    • 21.27. xmlrpc.server — Basic XML-RPC servers
      • 21.27.1. SimpleXMLRPCServer Objects
        • 21.27.1.1. SimpleXMLRPCServer Example
      • 21.27.2. CGIXMLRPCRequestHandler
      • 21.27.3. Documenting XMLRPC server
      • 21.27.4. DocXMLRPCServer Objects
      • 21.27.5. DocCGIXMLRPCRequestHandler
    • 21.28. ipaddress — IPv4/IPv6 manipulation library
      • 21.28.1. Convenience factory functions
      • 21.28.2. IP Addresses
        • 21.28.2.1. Address objects
        • 21.28.2.2. Conversion to Strings and Integers
        • 21.28.2.3. Operators
          • 21.28.2.3.1. Comparison operators
          • 21.28.2.3.2. Arithmetic operators
      • 21.28.3. IP Network definitions
        • 21.28.3.1. Prefix, net mask and host mask
        • 21.28.3.2. Network objects
        • 21.28.3.3. Operators
          • 21.28.3.3.1. Logical operators
          • 21.28.3.3.2. Iteration
          • 21.28.3.3.3. Networks as containers of addresses
      • 21.28.4. Interface objects
      • 21.28.5. Other Module Level Functions
      • 21.28.6. Custom Exceptions
  • 22. Multimedia Services
    • 22.1. audioop — Manipulate raw audio data
    • 22.2. aifc — Read and write AIFF and AIFC files
    • 22.3. sunau — Read and write Sun AU files
      • 22.3.1. AU_read Objects
      • 22.3.2. AU_write Objects
    • 22.4. wave — Read and write WAV files
      • 22.4.1. Wave_read Objects
      • 22.4.2. Wave_write Objects
    • 22.5. chunk — Read IFF chunked data
    • 22.6. colorsys — Conversions between color systems
    • 22.7. imghdr — Determine the type of an image
    • 22.8. sndhdr — Determine type of sound file
    • 22.9. ossaudiodev — Access to OSS-compatible audio devices
      • 22.9.1. Audio Device Objects
      • 22.9.2. Mixer Device Objects
  • 23. Internationalization
    • 23.1. gettext — Multilingual internationalization services
      • 23.1.1. GNU gettext API
      • 23.1.2. Class-based API
        • 23.1.2.1. The NullTranslations class
        • 23.1.2.2. The GNUTranslations class
        • 23.1.2.3. Solaris message catalog support
        • 23.1.2.4. The Catalog constructor
      • 23.1.3. Internationalizing your programs and modules
        • 23.1.3.1. Localizing your module
        • 23.1.3.2. Localizing your application
        • 23.1.3.3. Changing languages on the fly
        • 23.1.3.4. Deferred translations
      • 23.1.4. Acknowledgements
    • 23.2. locale — Internationalization services
      • 23.2.1. Background, details, hints, tips and caveats
      • 23.2.2. For extension writers and programs that embed Python
      • 23.2.3. Access to message catalogs
  • 24. Program Frameworks
    • 24.1. turtle — Turtle graphics
      • 24.1.1. Introduction
      • 24.1.2. Overview of available Turtle and Screen methods
        • 24.1.2.1. Turtle methods
        • 24.1.2.2. Methods of TurtleScreen/Screen
      • 24.1.3. Methods of RawTurtle/Turtle and corresponding functions
        • 24.1.3.1. Turtle motion
        • 24.1.3.2. Tell Turtle’s state
        • 24.1.3.3. Settings for measurement
        • 24.1.3.4. Pen control
          • 24.1.3.4.1. Drawing state
          • 24.1.3.4.2. Color control
          • 24.1.3.4.3. Filling
          • 24.1.3.4.4. More drawing control
        • 24.1.3.5. Turtle state
          • 24.1.3.5.1. Visibility
          • 24.1.3.5.2. Appearance
        • 24.1.3.6. Using events
        • 24.1.3.7. Special Turtle methods
        • 24.1.3.8. Compound shapes
      • 24.1.4. Methods of TurtleScreen/Screen and corresponding functions
        • 24.1.4.1. Window control
        • 24.1.4.2. Animation control
        • 24.1.4.3. Using screen events
        • 24.1.4.4. Input methods
        • 24.1.4.5. Settings and special methods
        • 24.1.4.6. Methods specific to Screen, not inherited from TurtleScreen
      • 24.1.5. Public classes
      • 24.1.6. Help and configuration
        • 24.1.6.1. How to use help
        • 24.1.6.2. Translation of docstrings into different languages
        • 24.1.6.3. How to configure Screen and Turtles
      • 24.1.7. turtledemo — Demo scripts
      • 24.1.8. Changes since Python 2.6
      • 24.1.9. Changes since Python 3.0
    • 24.2. cmd — Support for line-oriented command interpreters
      • 24.2.1. Cmd Objects
      • 24.2.2. Cmd Example
    • 24.3. shlex — Simple lexical analysis
      • 24.3.1. shlex Objects
      • 24.3.2. Parsing Rules
  • 25. Graphical User Interfaces with Tk
    • 25.1. tkinter — Python interface to Tcl/Tk
      • 25.1.1. Tkinter Modules
      • 25.1.2. Tkinter Life Preserver
        • 25.1.2.1. How To Use This Section
        • 25.1.2.2. A Simple Hello World Program
      • 25.1.3. A (Very) Quick Look at Tcl/Tk
      • 25.1.4. Mapping Basic Tk into Tkinter
      • 25.1.5. How Tk and Tkinter are Related
      • 25.1.6. Handy Reference
        • 25.1.6.1. Setting Options
        • 25.1.6.2. The Packer
        • 25.1.6.3. Packer Options
        • 25.1.6.4. Coupling Widget Variables
        • 25.1.6.5. The Window Manager
        • 25.1.6.6. Tk Option Data Types
        • 25.1.6.7. Bindings and Events
        • 25.1.6.8. The index Parameter
        • 25.1.6.9. Images
      • 25.1.7. File Handlers
    • 25.2. tkinter.ttk — Tk themed widgets
      • 25.2.1. Using Ttk
      • 25.2.2. Ttk Widgets
      • 25.2.3. Widget
        • 25.2.3.1. Standard Options
        • 25.2.3.2. Scrollable Widget Options
        • 25.2.3.3. Label Options
        • 25.2.3.4. Compatibility Options
        • 25.2.3.5. Widget States
        • 25.2.3.6. ttk.Widget
      • 25.2.4. Combobox
        • 25.2.4.1. Options
        • 25.2.4.2. Virtual events
        • 25.2.4.3. ttk.Combobox
      • 25.2.5. Notebook
        • 25.2.5.1. Options
        • 25.2.5.2. Tab Options
        • 25.2.5.3. Tab Identifiers
        • 25.2.5.4. Virtual Events
        • 25.2.5.5. ttk.Notebook
      • 25.2.6. Progressbar
        • 25.2.6.1. Options
        • 25.2.6.2. ttk.Progressbar
      • 25.2.7. Separator
        • 25.2.7.1. Options
      • 25.2.8. Sizegrip
        • 25.2.8.1. Platform-specific notes
        • 25.2.8.2. Bugs
      • 25.2.9. Treeview
        • 25.2.9.1. Options
        • 25.2.9.2. Item Options
        • 25.2.9.3. Tag Options
        • 25.2.9.4. Column Identifiers
        • 25.2.9.5. Virtual Events
        • 25.2.9.6. ttk.Treeview
      • 25.2.10. Ttk Styling
        • 25.2.10.1. Layouts
    • 25.3. tkinter.tix — Extension widgets for Tk
      • 25.3.1. Using Tix
      • 25.3.2. Tix Widgets
        • 25.3.2.1. Basic Widgets
        • 25.3.2.2. File Selectors
        • 25.3.2.3. Hierarchical ListBox
        • 25.3.2.4. Tabular ListBox
        • 25.3.2.5. Manager Widgets
        • 25.3.2.6. Image Types
        • 25.3.2.7. Miscellaneous Widgets
        • 25.3.2.8. Form Geometry Manager
      • 25.3.3. Tix Commands
    • 25.4. tkinter.scrolledtext — Scrolled Text Widget
    • 25.5. IDLE
      • 25.5.1. Menus
        • 25.5.1.1. File menu (Shell and Editor)
        • 25.5.1.2. Edit menu (Shell and Editor)
        • 25.5.1.3. Format menu (Editor window only)
        • 25.5.1.4. Run menu (Editor window only)
        • 25.5.1.5. Shell menu (Shell window only)
        • 25.5.1.6. Debug menu (Shell window only)
        • 25.5.1.7. Options menu (Shell and Editor)
        • 25.5.1.8. Window menu (Shell and Editor)
        • 25.5.1.9. Help menu (Shell and Editor)
        • 25.5.1.10. Context Menus
      • 25.5.2. Editing and navigation
        • 25.5.2.1. Automatic indentation
        • 25.5.2.2. Completions
        • 25.5.2.3. Python Shell window
      • 25.5.3. Syntax colors
      • 25.5.4. Startup
        • 25.5.4.1. Command line usage
        • 25.5.4.2. Running without a subprocess
      • 25.5.5. Help and preferences
        • 25.5.5.1. Additional help sources
        • 25.5.5.2. Setting preferences
        • 25.5.5.3. Extensions
    • 25.6. Other Graphical User Interface Packages
  • 26. Development Tools
    • 26.1. pydoc — Documentation generator and online help system
    • 26.2. doctest — Test interactive Python examples
      • 26.2.1. Simple Usage: Checking Examples in Docstrings
      • 26.2.2. Simple Usage: Checking Examples in a Text File
      • 26.2.3. How It Works
        • 26.2.3.1. Which Docstrings Are Examined?
        • 26.2.3.2. How are Docstring Examples Recognized?
        • 26.2.3.3. What’s the Execution Context?
        • 26.2.3.4. What About Exceptions?
        • 26.2.3.5. Option Flags
        • 26.2.3.6. Directives
        • 26.2.3.7. Warnings
      • 26.2.4. Basic API
      • 26.2.5. Unittest API
      • 26.2.6. Advanced API
        • 26.2.6.1. DocTest Objects
        • 26.2.6.2. Example Objects
        • 26.2.6.3. DocTestFinder objects
        • 26.2.6.4. DocTestParser objects
        • 26.2.6.5. DocTestRunner objects
        • 26.2.6.6. OutputChecker objects
      • 26.2.7. Debugging
      • 26.2.8. Soapbox
    • 26.3. unittest — Unit testing framework
      • 26.3.1. Basic example
      • 26.3.2. Command-Line Interface
        • 26.3.2.1. Command-line options
      • 26.3.3. Test Discovery
      • 26.3.4. Organizing test code
      • 26.3.5. Re-using old test code
      • 26.3.6. Skipping tests and expected failures
      • 26.3.7. Distinguishing test iterations using subtests
      • 26.3.8. Classes and functions
        • 26.3.8.1. Test cases
          • 26.3.8.1.1. Deprecated aliases
        • 26.3.8.2. Grouping tests
        • 26.3.8.3. Loading and running tests
          • 26.3.8.3.1. load_tests Protocol
      • 26.3.9. Class and Module Fixtures
        • 26.3.9.1. setUpClass and tearDownClass
        • 26.3.9.2. setUpModule and tearDownModule
      • 26.3.10. Signal Handling
    • 26.4. unittest.mock — mock object library
      • 26.4.1. Quick Guide
      • 26.4.2. The Mock Class
        • 26.4.2.1. Calling
        • 26.4.2.2. Deleting Attributes
        • 26.4.2.3. Mock names and the name attribute
        • 26.4.2.4. Attaching Mocks as Attributes
      • 26.4.3. The patchers
        • 26.4.3.1. patch
        • 26.4.3.2. patch.object
        • 26.4.3.3. patch.dict
        • 26.4.3.4. patch.multiple
        • 26.4.3.5. patch methods: start and stop
        • 26.4.3.6. TEST_PREFIX
        • 26.4.3.7. Nesting Patch Decorators
        • 26.4.3.8. Where to patch
        • 26.4.3.9. Patching Descriptors and Proxy Objects
      • 26.4.4. MagicMock and magic method support
        • 26.4.4.1. Mocking Magic Methods
        • 26.4.4.2. Magic Mock
      • 26.4.5. Helpers
        • 26.4.5.1. sentinel
        • 26.4.5.2. DEFAULT
        • 26.4.5.3. call
        • 26.4.5.4. create_autospec
        • 26.4.5.5. ANY
        • 26.4.5.6. FILTER_DIR
        • 26.4.5.7. mock_open
        • 26.4.5.8. Autospeccing
    • 26.5. unittest.mock — getting started
      • 26.5.1. Using Mock
        • 26.5.1.1. Mock Patching Methods
        • 26.5.1.2. Mock for Method Calls on an Object
        • 26.5.1.3. Mocking Classes
        • 26.5.1.4. Naming your mocks
        • 26.5.1.5. Tracking all Calls
        • 26.5.1.6. Setting Return Values and Attributes
        • 26.5.1.7. Raising exceptions with mocks
        • 26.5.1.8. Side effect functions and iterables
        • 26.5.1.9. Creating a Mock from an Existing Object
      • 26.5.2. Patch Decorators
      • 26.5.3. Further Examples
        • 26.5.3.1. Mocking chained calls
        • 26.5.3.2. Partial mocking
        • 26.5.3.3. Mocking a Generator Method
        • 26.5.3.4. Applying the same patch to every test method
        • 26.5.3.5. Mocking Unbound Methods
        • 26.5.3.6. Checking multiple calls with mock
        • 26.5.3.7. Coping with mutable arguments
        • 26.5.3.8. Nesting Patches
        • 26.5.3.9. Mocking a dictionary with MagicMock
        • 26.5.3.10. Mock subclasses and their attributes
        • 26.5.3.11. Mocking imports with patch.dict
        • 26.5.3.12. Tracking order of calls and less verbose call assertions
        • 26.5.3.13. More complex argument matching
    • 26.6. 2to3 - Automated Python 2 to 3 code translation
      • 26.6.1. Using 2to3
      • 26.6.2. Fixers
      • 26.6.3. lib2to3 - 2to3’s library
    • 26.7. test — Regression tests package for Python
      • 26.7.1. Writing Unit Tests for the test package
      • 26.7.2. Running tests using the command-line interface
    • 26.8. test.support — Utilities for the Python test suite
  • 27. Debugging and Profiling
    • 27.1. bdb — Debugger framework
    • 27.2. faulthandler — Dump the Python traceback
      • 27.2.1. Dumping the traceback
      • 27.2.2. Fault handler state
      • 27.2.3. Dumping the tracebacks after a timeout
      • 27.2.4. Dumping the traceback on a user signal
      • 27.2.5. Issue with file descriptors
      • 27.2.6. Example
    • 27.3. pdb — The Python Debugger
      • 27.3.1. Debugger Commands
    • 27.4. The Python Profilers
      • 27.4.1. Introduction to the profilers
      • 27.4.2. Instant User’s Manual
      • 27.4.3. profile and cProfile Module Reference
      • 27.4.4. The Stats Class
      • 27.4.5. What Is Deterministic Profiling?
      • 27.4.6. Limitations
      • 27.4.7. Calibration
      • 27.4.8. Using a custom timer
    • 27.5. timeit — Measure execution time of small code snippets
      • 27.5.1. Basic Examples
      • 27.5.2. Python Interface
      • 27.5.3. Command-Line Interface
      • 27.5.4. Examples
    • 27.6. trace — Trace or track Python statement execution
      • 27.6.1. Command-Line Usage
        • 27.6.1.1. Main options
        • 27.6.1.2. Modifiers
        • 27.6.1.3. Filters
      • 27.6.2. Programmatic Interface
    • 27.7. tracemalloc — Trace memory allocations
      • 27.7.1. Examples
        • 27.7.1.1. Display the top 10
        • 27.7.1.2. Compute differences
        • 27.7.1.3. Get the traceback of a memory block
        • 27.7.1.4. Pretty top
      • 27.7.2. API
        • 27.7.2.1. Functions
        • 27.7.2.2. Filter
        • 27.7.2.3. Frame
        • 27.7.2.4. Snapshot
        • 27.7.2.5. Statistic
        • 27.7.2.6. StatisticDiff
        • 27.7.2.7. Trace
        • 27.7.2.8. Traceback
  • 28. Software Packaging and Distribution
    • 28.1. distutils — Building and installing Python modules
    • 28.2. ensurepip — Bootstrapping the pip installer
      • 28.2.1. Command line interface
      • 28.2.2. Module API
    • 28.3. venv — Creation of virtual environments
      • 28.3.1. Creating virtual environments
      • 28.3.2. API
      • 28.3.3. An example of extending EnvBuilder
  • 29. Python Runtime Services
    • 29.1. sys — System-specific parameters and functions
    • 29.2. sysconfig — Provide access to Python’s configuration information
      • 29.2.1. Configuration variables
      • 29.2.2. Installation paths
      • 29.2.3. Other functions
      • 29.2.4. Using sysconfig as a script
    • 29.3. builtins — Built-in objects
    • 29.4. __main__ — Top-level script environment
    • 29.5. warnings — Warning control
      • 29.5.1. Warning Categories
      • 29.5.2. The Warnings Filter
        • 29.5.2.1. Default Warning Filters
      • 29.5.3. Temporarily Suppressing Warnings
      • 29.5.4. Testing Warnings
      • 29.5.5. Updating Code For New Versions of Python
      • 29.5.6. Available Functions
      • 29.5.7. Available Context Managers
    • 29.6. contextlib — Utilities for with-statement contexts
      • 29.6.1. Utilities
      • 29.6.2. Examples and Recipes
        • 29.6.2.1. Supporting a variable number of context managers
        • 29.6.2.2. Simplifying support for single optional context managers
        • 29.6.2.3. Catching exceptions from __enter__ methods
        • 29.6.2.4. Cleaning up in an __enter__ implementation
        • 29.6.2.5. Replacing any use of try-finally and flag variables
        • 29.6.2.6. Using a context manager as a function decorator
      • 29.6.3. Single use, reusable and reentrant context managers
        • 29.6.3.1. Reentrant context managers
        • 29.6.3.2. Reusable context managers
    • 29.7. abc — Abstract Base Classes
    • 29.8. atexit — Exit handlers
      • 29.8.1. atexit Example
    • 29.9. traceback — Print or retrieve a stack traceback
      • 29.9.1. Traceback Examples
    • 29.10. __future__ — Future statement definitions
    • 29.11. gc — Garbage Collector interface
    • 29.12. inspect — Inspect live objects
      • 29.12.1. Types and members
      • 29.12.2. Retrieving source code
      • 29.12.3. Introspecting callables with the Signature object
      • 29.12.4. Classes and functions
      • 29.12.5. The interpreter stack
      • 29.12.6. Fetching attributes statically
      • 29.12.7. Current State of a Generator
      • 29.12.8. Command Line Interface
    • 29.13. site — Site-specific configuration hook
      • 29.13.1. Readline configuration
      • 29.13.2. Module contents
    • 29.14. fpectl — Floating point exception control
      • 29.14.1. Example
      • 29.14.2. Limitations and other considerations
  • 30. Custom Python Interpreters
    • 30.1. code — Interpreter base classes
      • 30.1.1. Interactive Interpreter Objects
      • 30.1.2. Interactive Console Objects
    • 30.2. codeop — Compile Python code
  • 31. Importing Modules
    • 31.1. zipimport — Import modules from Zip archives
      • 31.1.1. zipimporter Objects
      • 31.1.2. Examples
    • 31.2. pkgutil — Package extension utility
    • 31.3. modulefinder — Find modules used by a script
      • 31.3.1. Example usage of ModuleFinder
    • 31.4. runpy — Locating and executing Python modules
    • 31.5. importlib – The implementation of import
      • 31.5.1. Introduction
      • 31.5.2. Functions
      • 31.5.3. importlib.abc – Abstract base classes related to import
      • 31.5.4. importlib.machinery – Importers and path hooks
      • 31.5.5. importlib.util – Utility code for importers
  • 32. Python Language Services
    • 32.1. parser — Access Python parse trees
      • 32.1.1. Creating ST Objects
      • 32.1.2. Converting ST Objects
      • 32.1.3. Queries on ST Objects
      • 32.1.4. Exceptions and Error Handling
      • 32.1.5. ST Objects
      • 32.1.6. Example: Emulation of compile()
    • 32.2. ast — Abstract Syntax Trees
      • 32.2.1. Node classes
      • 32.2.2. Abstract Grammar
      • 32.2.3. ast Helpers
    • 32.3. symtable — Access to the compiler’s symbol tables
      • 32.3.1. Generating Symbol Tables
      • 32.3.2. Examining Symbol Tables
    • 32.4. symbol — Constants used with Python parse trees
    • 32.5. token — Constants used with Python parse trees
    • 32.6. keyword — Testing for Python keywords
    • 32.7. tokenize — Tokenizer for Python source
      • 32.7.1. Tokenizing Input
      • 32.7.2. Command-Line Usage
      • 32.7.3. Examples
    • 32.8. tabnanny — Detection of ambiguous indentation
    • 32.9. pyclbr — Python class browser support
      • 32.9.1. Class Objects
      • 32.9.2. Function Objects
    • 32.10. py_compile — Compile Python source files
    • 32.11. compileall — Byte-compile Python libraries
      • 32.11.1. Command-line use
      • 32.11.2. Public functions
    • 32.12. dis — Disassembler for Python bytecode
      • 32.12.1. Bytecode analysis
      • 32.12.2. Analysis functions
      • 32.12.3. Python Bytecode Instructions
      • 32.12.4. Opcode collections
    • 32.13. pickletools — Tools for pickle developers
      • 32.13.1. Command line usage
        • 32.13.1.1. Command line options
      • 32.13.2. Programmatic Interface
  • 33. Miscellaneous Services
    • 33.1. formatter — Generic output formatting
      • 33.1.1. The Formatter Interface
      • 33.1.2. Formatter Implementations
      • 33.1.3. The Writer Interface
      • 33.1.4. Writer Implementations
  • 34. MS Windows Specific Services
    • 34.1. msilib — Read and write Microsoft Installer files
      • 34.1.1. Database Objects
      • 34.1.2. View Objects
      • 34.1.3. Summary Information Objects
      • 34.1.4. Record Objects
      • 34.1.5. Errors
      • 34.1.6. CAB Objects
      • 34.1.7. Directory Objects
      • 34.1.8. Features
      • 34.1.9. GUI classes
      • 34.1.10. Precomputed tables
    • 34.2. msvcrt – Useful routines from the MS VC++ runtime
      • 34.2.1. File Operations
      • 34.2.2. Console I/O
      • 34.2.3. Other Functions
    • 34.3. winreg – Windows registry access
      • 34.3.1. Functions
      • 34.3.2. Constants
        • 34.3.2.1. HKEY_* Constants
        • 34.3.2.2. Access Rights
          • 34.3.2.2.1. 64-bit Specific
        • 34.3.2.3. Value Types
      • 34.3.3. Registry Handle Objects
    • 34.4. winsound — Sound-playing interface for Windows
  • 35. Unix Specific Services
    • 35.1. posix — The most common POSIX system calls
      • 35.1.1. Large File Support
      • 35.1.2. Notable Module Contents
    • 35.2. pwd — The password database
    • 35.3. spwd — The shadow password database
    • 35.4. grp — The group database
    • 35.5. crypt — Function to check Unix passwords
      • 35.5.1. Hashing Methods
      • 35.5.2. Module Attributes
      • 35.5.3. Module Functions
      • 35.5.4. Examples
    • 35.6. termios — POSIX style tty control
      • 35.6.1. Example
    • 35.7. tty — Terminal control functions
    • 35.8. pty — Pseudo-terminal utilities
      • 35.8.1. Example
    • 35.9. fcntl — The fcntl and ioctl system calls
    • 35.10. pipes — Interface to shell pipelines
      • 35.10.1. Template Objects
    • 35.11. resource — Resource usage information
      • 35.11.1. Resource Limits
      • 35.11.2. Resource Usage
    • 35.12. nis — Interface to Sun’s NIS (Yellow Pages)
    • 35.13. syslog — Unix syslog library routines
      • 35.13.1. Examples
        • 35.13.1.1. Simple example
  • 36. Superseded Modules
    • 36.1. optparse — Parser for command line options
      • 36.1.1. Background
        • 36.1.1.1. Terminology
        • 36.1.1.2. What are options for?
        • 36.1.1.3. What are positional arguments for?
      • 36.1.2. Tutorial
        • 36.1.2.1. Understanding option actions
        • 36.1.2.2. The store action
        • 36.1.2.3. Handling boolean (flag) options
        • 36.1.2.4. Other actions
        • 36.1.2.5. Default values
        • 36.1.2.6. Generating help
          • 36.1.2.6.1. Grouping Options
        • 36.1.2.7. Printing a version string
        • 36.1.2.8. How optparse handles errors
        • 36.1.2.9. Putting it all together
      • 36.1.3. Reference Guide
        • 36.1.3.1. Creating the parser
        • 36.1.3.2. Populating the parser
        • 36.1.3.3. Defining options
        • 36.1.3.4. Option attributes
        • 36.1.3.5. Standard option actions
        • 36.1.3.6. Standard option types
        • 36.1.3.7. Parsing arguments
        • 36.1.3.8. Querying and manipulating your option parser
        • 36.1.3.9. Conflicts between options
        • 36.1.3.10. Cleanup
        • 36.1.3.11. Other methods
      • 36.1.4. Option Callbacks
        • 36.1.4.1. Defining a callback option
        • 36.1.4.2. How callbacks are called
        • 36.1.4.3. Raising errors in a callback
        • 36.1.4.4. Callback example 1: trivial callback
        • 36.1.4.5. Callback example 2: check option order
        • 36.1.4.6. Callback example 3: check option order (generalized)
        • 36.1.4.7. Callback example 4: check arbitrary condition
        • 36.1.4.8. Callback example 5: fixed arguments
        • 36.1.4.9. Callback example 6: variable arguments
      • 36.1.5. Extending optparse
        • 36.1.5.1. Adding new types
        • 36.1.5.2. Adding new actions
    • 36.2. imp — Access the import internals
      • 36.2.1. Examples
  • 37. Undocumented Modules
    • 37.1. Platform specific modules
• Extending and Embedding the Python Interpreter
  • Recommended third party tools
  • Creating extensions without third party tools
    • 1. Extending Python with C or C++
      • 1.1. A Simple Example
      • 1.2. Intermezzo: Errors and Exceptions
      • 1.3. Back to the Example
      • 1.4. The Module’s Method Table and Initialization Function
      • 1.5. Compilation and Linkage
      • 1.6. Calling Python Functions from C
      • 1.7. Extracting Parameters in Extension Functions
      • 1.8. Keyword Parameters for Extension Functions
      • 1.9. Building Arbitrary Values
      • 1.10. Reference Counts
        • 1.10.1. Reference Counting in Python
        • 1.10.2. Ownership Rules
        • 1.10.3. Thin Ice
        • 1.10.4. NULL Pointers
      • 1.11. Writing Extensions in C++
      • 1.12. Providing a C API for an Extension Module
    • 2. Defining New Types
      • 2.1. The Basics
        • 2.1.1. Adding data and methods to the Basic example
        • 2.1.2. Providing finer control over data attributes
        • 2.1.3. Supporting cyclic garbage collection
        • 2.1.4. Subclassing other types
      • 2.2. Type Methods
        • 2.2.1. Finalization and De-allocation
        • 2.2.2. Object Presentation
        • 2.2.3. Attribute Management
          • 2.2.3.1. Generic Attribute Management
          • 2.2.3.2. Type-specific Attribute Management
        • 2.2.4. Object Comparison
        • 2.2.5. Abstract Protocol Support
        • 2.2.6. Weak Reference Support
        • 2.2.7. More Suggestions
    • 3. Building C and C++ Extensions with distutils
      • 3.1. Distributing your extension modules
    • 4. Building C and C++ Extensions on Windows
      • 4.1. A Cookbook Approach
      • 4.2. Differences Between Unix and Windows
      • 4.3. Using DLLs in Practice
  • Embedding the CPython runtime in a larger application
    • 1. Embedding Python in Another Application
      • 1.1. Very High Level Embedding
      • 1.2. Beyond Very High Level Embedding: An overview
      • 1.3. Pure Embedding
      • 1.4. Extending Embedded Python
      • 1.5. Embedding Python in C++
      • 1.6. Compiling and Linking under Unix-like systems
• Python/C API Reference Manual
  • Introduction
    • Include Files
    • Objects, Types and Reference Counts
      • Reference Counts
        • Reference Count Details
      • Types
    • Exceptions
    • Embedding Python
    • Debugging Builds
  • Stable Application Binary Interface
  • The Very High Level Layer
  • Reference Counting
  • Exception Handling
    • Exception Objects
    • Unicode Exception Objects
    • Recursion Control
    • Standard Exceptions
  • Utilities
    • Operating System Utilities
    • System Functions
    • Process Control
    • Importing Modules
    • Data marshalling support
    • Parsing arguments and building values
      • Parsing arguments
        • Strings and buffers
        • Numbers
        • Other objects
        • API Functions
      • Building values
    • String conversion and formatting
    • Reflection
    • Codec registry and support functions
      • Codec lookup API
      • Registry API for Unicode encoding error handlers
  • Abstract Objects Layer
    • Object Protocol
    • Number Protocol
    • Sequence Protocol
    • Mapping Protocol
    • Iterator Protocol
    • Buffer Protocol
      • Buffer structure
      • Buffer request types
        • request-independent fields
        • readonly, format
        • shape, strides, suboffsets
        • contiguity requests
        • compound requests
      • Complex arrays
        • NumPy-style: shape and strides
        • PIL-style: shape, strides and suboffsets
      • Buffer-related functions
    • Old Buffer Protocol
  • Concrete Objects Layer
    • Fundamental Objects
      • Type Objects
      • The None Object
    • Numeric Objects
      • Integer Objects
      • Boolean Objects
      • Floating Point Objects
      • Complex Number Objects
        • Complex Numbers as C Structures
        • Complex Numbers as Python Objects
    • Sequence Objects
      • Bytes Objects
      • Byte Array Objects
        • Type check macros
        • Direct API functions
        • Macros
      • Unicode Objects and Codecs
        • Unicode Objects
          • Unicode Type
          • Unicode Character Properties
          • Creating and accessing Unicode strings
          • Deprecated Py_UNICODE APIs
          • Locale Encoding
          • File System Encoding
          • wchar_t Support
          • UCS4 Support
        • Built-in Codecs
          • Generic Codecs
          • UTF-8 Codecs
          • UTF-32 Codecs
          • UTF-16 Codecs
          • UTF-7 Codecs
          • Unicode-Escape Codecs
          • Raw-Unicode-Escape Codecs
          • Latin-1 Codecs
          • ASCII Codecs
          • Character Map Codecs
          • MBCS codecs for Windows
          • Methods & Slots
        • Methods and Slot Functions
      • Tuple Objects
      • Struct Sequence Objects
      • List Objects
    • Container Objects
      • Dictionary Objects
      • Set Objects
    • Function Objects
      • Function Objects
      • Instance Method Objects
      • Method Objects
      • Cell Objects
      • Code Objects
    • Other Objects
      • File Objects
      • Module Objects
        • Initializing C modules
      • Iterator Objects
      • Descriptor Objects
      • Slice Objects
      • MemoryView objects
      • Weak Reference Objects
      • Capsules
      • Generator Objects
      • DateTime Objects
  • Initialization, Finalization, and Threads
    • Initializing and finalizing the interpreter
    • Process-wide parameters
    • Thread State and the Global Interpreter Lock
      • Releasing the GIL from extension code
      • Non-Python created threads
      • High-level API
      • Low-level API
    • Sub-interpreter support
      • Bugs and caveats
    • Asynchronous Notifications
    • Profiling and Tracing
    • Advanced Debugger Support
  • Memory Management
    • Overview
    • Raw Memory Interface
    • Memory Interface
    • Customize Memory Allocators
    • Customize PyObject Arena Allocator
    • Examples
  • Object Implementation Support
    • Allocating Objects on the Heap
    • Common Object Structures
    • Type Objects
    • Number Object Structures
    • Mapping Object Structures
    • Sequence Object Structures
    • Buffer Object Structures
    • Supporting Cyclic Garbage Collection
  • API and ABI Versioning
• Distributing Python Modules
  • Key terms
  • Open source licensing and collaboration
  • Installing the tools
  • Reading the guide
  • How do I...?
    • ... choose a name for my project?
    • ... create and distribute binary extensions?
• Installing Python Modules
  • Key terms
  • Basic usage
  • How do I ...?
    • ... install pip in versions of Python prior to Python 3.4?
    • ... install packages just for the current user?
    • ... install scientific Python packages?
    • ... work with multiple versions of Python installed in parallel?
  • Common installation issues
    • Installing into the system Python on Linux
    • Installing binary extensions
• Python HOWTOs
  • Porting Python 2 Code to Python 3
    • The Short Explanation
    • Details
      • Drop support for Python 2.6 and older
      • Make sure you specify the proper version support in your setup.py file
      • Have good test coverage
      • Learn the differences between Python 2 & 3
      • Update your code
        • Division
        • Text versus binary data
      • Prevent compatibility regressions
      • Check which dependencies block your transition
      • Update your setup.py file to denote Python 3 compatibility
      • Use continuous integration to stay compatible
    • Dropping Python 2 support completely
  • Porting Extension Modules to Python 3
    • Conditional compilation
    • Changes to Object APIs
      • str/unicode Unification
      • long/int Unification
    • Module initialization and state
    • CObject replaced with Capsule
    • Other options
  • Curses Programming with Python
    • What is curses?
      • The Python curses module
    • Starting and ending a curses application
    • Windows and Pads
    • Displaying Text
      • Attributes and Color
    • User Input
    • For More Information
  • Descriptor HowTo Guide
    • Abstract
    • Definition and Introduction
    • Descriptor Protocol
    • Invoking Descriptors
    • Descriptor Example
    • Properties
    • Functions and Methods
    • Static Methods and Class Methods
  • Functional Programming HOWTO
    • Introduction
      • Formal provability
      • Modularity
      • Ease of debugging and testing
      • Composability
    • Iterators
      • Data Types That Support Iterators
    • Generator expressions and list comprehensions
    • Generators
      • Passing values into a generator
    • Built-in functions
    • The itertools module
      • Creating new iterators
      • Calling functions on elements
      • Selecting elements
      • Combinatoric functions
      • Grouping elements
    • The functools module
      • The operator module
    • Small functions and the lambda expression
    • Revision History and Acknowledgements
    • References
      • General
      • Python-specific
      • Python documentation
  • Logging HOWTO
    • Basic Logging Tutorial
      • When to use logging
      • A simple example
      • Logging to a file
      • Logging from multiple modules
      • Logging variable data
      • Changing the format of displayed messages
      • Displaying the date/time in messages
      • Next Steps
    • Advanced Logging Tutorial
      • Logging Flow
      • Loggers
      • Handlers
      • Formatters
      • Configuring Logging
      • What happens if no configuration is provided
      • Configuring Logging for a Library
    • Logging Levels
      • Custom Levels
    • Useful Handlers
    • Exceptions raised during logging
    • Using arbitrary objects as messages
    • Optimization
  • Logging Cookbook
    • Using logging in multiple modules
    • Multiple handlers and formatters
    • Logging to multiple destinations
    • Configuration server example
    • Dealing with handlers that block
    • Sending and receiving logging events across a network
    • Adding contextual information to your logging output
      • Using LoggerAdapters to impart contextual information
        • Using objects other than dicts to pass contextual information
      • Using Filters to impart contextual information
    • Logging to a single file from multiple processes
    • Using file rotation
    • Use of alternative formatting styles
    • Customizing LogRecord
    • Subclassing QueueHandler - a ZeroMQ example
    • Subclassing QueueListener - a ZeroMQ example
    • An example dictionary-based configuration
    • Using a rotator and namer to customize log rotation processing
    • A more elaborate multiprocessing example
    • Inserting a BOM into messages sent to a SysLogHandler
    • Implementing structured logging
    • Customizing handlers with dictConfig()
    • Using particular formatting styles throughout your application
      • Using LogRecord factories
      • Using custom message objects
    • Configuring filters with dictConfig()
    • Customized exception formatting
    • Speaking logging messages
  • Regular Expression HOWTO
    • Introduction
    • Simple Patterns
      • Matching Characters
      • Repeating Things
    • Using Regular Expressions
      • Compiling Regular Expressions
      • The Backslash Plague
      • Performing Matches
      • Module-Level Functions
      • Compilation Flags
    • More Pattern Power
      • More Metacharacters
      • Grouping
      • Non-capturing and Named Groups
      • Lookahead Assertions
    • Modifying Strings
      • Splitting Strings
      • Search and Replace
    • Common Problems
      • Use String Methods
      • match() versus search()
      • Greedy versus Non-Greedy
      • Using re.VERBOSE
    • Feedback
  • Socket Programming HOWTO
    • Sockets
      • History
    • Creating a Socket
      • IPC
    • Using a Socket
      • Binary Data
    • Disconnecting
      • When Sockets Die
    • Non-blocking Sockets
  • Sorting HOW TO
    • Sorting Basics
    • Key Functions
    • Operator Module Functions
    • Ascending and Descending
    • Sort Stability and Complex Sorts
    • The Old Way Using Decorate-Sort-Undecorate
    • The Old Way Using the cmp Parameter
    • Odd and Ends
  • Unicode HOWTO
    • Introduction to Unicode
      • History of Character Codes
      • Definitions
      • Encodings
      • References
    • Python’s Unicode Support
      • The String Type
      • Converting to Bytes
      • Unicode Literals in Python Source Code
      • Unicode Properties
      • Unicode Regular Expressions
      • References
    • Reading and Writing Unicode Data
      • Unicode filenames
      • Tips for Writing Unicode-aware Programs
        • Converting Between File Encodings
        • Files in an Unknown Encoding
      • References
    • Acknowledgements
  • HOWTO Fetch Internet Resources Using The urllib Package
    • Introduction
    • Fetching URLs
      • Data
      • Headers
    • Handling Exceptions
      • URLError
      • HTTPError
        • Error Codes
      • Wrapping it Up
        • Number 1
        • Number 2
    • info and geturl
    • Openers and Handlers
    • Basic Authentication
    • Proxies
    • Sockets and Layers
    • Footnotes
  • HOWTO Use Python in the web
    • The Low-Level View
      • Common Gateway Interface
        • Simple script for testing CGI
        • Setting up CGI on your own server
        • Common problems with CGI scripts
      • mod_python
      • FastCGI and SCGI
        • Setting up FastCGI
      • mod_wsgi
    • Step back: WSGI
      • WSGI Servers
      • Case study: MoinMoin
    • Model-View-Controller
    • Ingredients for Websites
      • Templates
      • Data persistence
    • Frameworks
      • Some notable frameworks
        • Django
        • TurboGears
        • Zope
        • Other notable frameworks
  • Argparse Tutorial
    • Concepts
    • The basics
    • Introducing Positional arguments
    • Introducing Optional arguments
      • Short options
    • Combining Positional and Optional arguments
    • Getting a little more advanced
      • Conflicting options
    • Conclusion
  • An introduction to the ipaddress module
    • Creating Address/Network/Interface objects
      • A Note on IP Versions
      • IP Host Addresses
      • Defining Networks
      • Host Interfaces
    • Inspecting Address/Network/Interface Objects
    • Networks as lists of Addresses
    • Comparisons
    • Using IP Addresses with other modules
    • Getting more detail when instance creation fails
  • Argument Clinic How-To
    • The Goals Of Argument Clinic
    • Basic Concepts And Usage
    • Converting Your First Function
    • Advanced Topics
      • Symbolic default values
      • Renaming the C functions and variables generated by Argument Clinic
      • Converting functions using PyArg_UnpackTuple
      • Optional Groups
      • Using real Argument Clinic converters, instead of “legacy converters”
      • Py_buffer
      • Advanced converters
      • Parameter default values
      • The NULL default value
      • Expressions specified as default values
      • Using a return converter
      • Cloning existing functions
      • Calling Python code
      • Using a “self converter”
      • Writing a custom converter
      • Writing a custom return converter
      • METH_O and METH_NOARGS
      • tp_new and tp_init functions
      • Changing and redirecting Clinic’s output
      • The #ifdef trick
      • Using Argument Clinic in Python files
• Python Frequently Asked Questions
  • General Python FAQ
    • General Information
    • Python in the real world
  • Programming FAQ
    • General Questions
    • Core Language
    • Numbers and strings
    • Performance
    • Sequences (Tuples/Lists)
    • Dictionaries
    • Objects
    • Modules
  • Design and History FAQ
    • Why does Python use indentation for grouping of statements?
    • Why am I getting strange results with simple arithmetic operations?
    • Why are floating-point calculations so inaccurate?
    • Why are Python strings immutable?
    • Why must ‘self’ be used explicitly in method definitions and calls?
    • Why can’t I use an assignment in an expression?
    • Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?
    • Why is join() a string method instead of a list or tuple method?
    • How fast are exceptions?
    • Why isn’t there a switch or case statement in Python?
    • Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?
    • Why can’t lambda expressions contain statements?
    • Can Python be compiled to machine code, C or some other language?
    • How does Python manage memory?
    • Why doesn’t CPython use a more traditional garbage collection scheme?
    • Why isn’t all memory freed when CPython exits?
    • Why are there separate tuple and list data types?
    • How are lists implemented?
    • How are dictionaries implemented?
    • Why must dictionary keys be immutable?
    • Why doesn’t list.sort() return the sorted list?
    • How do you specify and enforce an interface spec in Python?
    • Why is there no goto?
    • Why can’t raw strings (r-strings) end with a backslash?
    • Why doesn’t Python have a “with” statement for attribute assignments?
    • Why are colons required for the if/while/def/class statements?
    • Why does Python allow commas at the end of lists and tuples?
  • Library and Extension FAQ
    • General Library Questions
    • Common tasks
    • Threads
    • Input and Output
    • Network/Internet Programming
    • Databases
    • Mathematics and Numerics
  • Extending/Embedding FAQ
    • Can I create my own functions in C?
    • Can I create my own functions in C++?
    • Writing C is hard; are there any alternatives?
    • How can I execute arbitrary Python statements from C?
    • How can I evaluate an arbitrary Python expression from C?
    • How do I extract C values from a Python object?
    • How do I use Py_BuildValue() to create a tuple of arbitrary length?
    • How do I call an object’s method from C?
    • How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?
    • How do I access a module written in Python from C?
    • How do I interface to C++ objects from Python?
    • I added a module using the Setup file and the make fails; why?
    • How do I debug an extension?
    • I want to compile a Python module on my Linux system, but some files are missing. Why?
    • What does “SystemError: _PyImport_FixupExtension: module yourmodule not loaded” mean?
    • How do I tell “incomplete input” from “invalid input”?
    • How do I find undefined g++ symbols __builtin_new or __pure_virtual?
    • Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?
  • Python on Windows FAQ
    • How do I run a Python program under Windows?
    • How do I make Python scripts executable?
    • Why does Python sometimes take so long to start?
    • How do I make an executable from a Python script?
    • Is a *.pyd file the same as a DLL?
    • How can I embed Python into a Windows application?
    • How do I keep editors from inserting tabs into my Python source?
    • How do I check for a keypress without blocking?
    • How do I emulate os.kill() in Windows?
    • How do I extract the downloaded documentation on Windows?
  • Graphic User Interface FAQ
    • General GUI Questions
    • What platform-independent GUI toolkits exist for Python?
    • What platform-specific GUI toolkits exist for Python?
    • Tkinter questions
  • “Why is Python Installed on my Computer?” FAQ
    • What is Python?
    • Why is Python installed on my machine?
    • Can I delete Python?
• Glossary
• About these documents
  • Contributors to the Python Documentation
• Reporting Bugs
  • Documentation bugs
  • Using the Python issue tracker
  • Getting started contributing to Python yourself
• Copyright
• History and License
  • History of the software
  • Terms and conditions for accessing or otherwise using Python
  • Licenses and Acknowledgements for Incorporated Software
    • Mersenne Twister
    • Sockets
    • Floating point exception control
    • Asynchronous socket services
    • Cookie management
    • Execution tracing
    • UUencode and UUdecode functions
    • XML Remote Procedure Calls
    • test_epoll
    • Select kqueue
    • SipHash24
    • strtod and dtoa
    • OpenSSL
    • expat
    • libffi
    • zlib
    • cfuhash
    • libmpdec