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if_pyth.txt For Vim version 7.4. Last change: 2015 Nov 10 VIM REFERENCE MANUAL by Paul Moore The Python Interface to Vim python Python 1. Commands python-commands 2. The vim module python-vim 3. Buffer objects python-buffer 4. Range objects python-range 5. Window objects python-window 6. Tab page objects python-tabpage 7. vim.bindeval objects python-bindeval-objects 8. pyeval(), py3eval() Vim functions python-pyeval 9. Dynamic loading python-dynamic 10. Python 3 python3 {Vi does not have any of these commands} The Python 2.x interface is available only when Vim was compiled with the +python feature. The Python 3 interface is available only when Vim was compiled with the +python3 feature. Both can be available at the same time, but read python-2-and-3. ============================================================================== 1. Commands python-commands :python :py E263 E264 E887 :[range]py[thon] {stmt} Execute Python statement {stmt}. A simple check if the :python command is working: :python print "Hello" :[range]py[thon] << {endmarker} {script} {endmarker} Execute Python script {script}. Note: This command doesn't work when the Python feature wasn't compiled in. To avoid errors, see script-here. {endmarker} must NOT be preceded by any white space. If {endmarker} is omitted from after the "<<", a dot '.' must be used after {script}, like for the :append and :insert commands. This form of the :python command is mainly useful for including python code in Vim scripts. Example: function! IcecreamInitialize() python << EOF class StrawberryIcecream: def __call__(self): print 'EAT ME' EOF endfunction Note: Python is very sensitive to the indenting. Make sure the "class" line and "EOF" do not have any indent. :pydo :[range]pydo {body} Execute Python function "def _vim_pydo(line, linenr): {body}" for each line in the [range], with the function arguments being set to the text of each line in turn, without a trailing <EOL>, and the current line number. The function should return a string or None. If a string is returned, it becomes the text of the line in the current turn. The default for [range] is the whole file: "1,$". {not in Vi} Examples: :pydo return "%s\t%d" % (line[::-1], len(line)) :pydo if line: return "%4d: %s" % (linenr, line) :pyfile :pyf :[range]pyf[ile] {file} Execute the Python script in {file}. The whole argument is used as a single file name. {not in Vi} Both of these commands do essentially the same thing - they execute a piece of Python code, with the "current range" python-range set to the given line range. In the case of :python, the code to execute is in the command-line. In the case of :pyfile, the code to execute is the contents of the given file. Python commands cannot be used in the sandbox. To pass arguments you need to set sys.argv[] explicitly. Example: :python import sys :python sys.argv = ["foo", "bar"] :pyfile myscript.py Here are some examples python-examples :python from vim import * :python from string import upper :python current.line = upper(current.line) :python print "Hello" :python str = current.buffer[42] (Note that changes - like the imports - persist from one command to the next, just like in the Python interpreter.) ============================================================================== 2. The vim module python-vim Python code gets all of its access to vim (with one exception - see python-output below) via the "vim" module. The vim module implements two methods, three constants, and one error object. You need to import the vim module before using it: :python import vim Overview :py print "Hello" # displays a message :py vim.command(cmd) # execute an Ex command :py w = vim.windows[n] # gets window "n" :py cw = vim.current.window # gets the current window :py b = vim.buffers[n] # gets buffer "n" :py cb = vim.current.buffer # gets the current buffer :py w.height = lines # sets the window height :py w.cursor = (row, col) # sets the window cursor position :py pos = w.cursor # gets a tuple (row, col) :py name = b.name # gets the buffer file name :py line = b[n] # gets a line from the buffer :py lines = b[n:m] # gets a list of lines :py num = len(b) # gets the number of lines :py b[n] = str # sets a line in the buffer :py b[n:m] = [str1, str2, str3] # sets a number of lines at once :py del b[n] # deletes a line :py del b[n:m] # deletes a number of lines Methods of the "vim" module vim.command(str) python-command Executes the vim (ex-mode) command str. Returns None. Examples: :py vim.command("set tw=72") :py vim.command("%s/aaa/bbb/g") The following definition executes Normal mode commands: def normal(str): vim.command("normal "+str) # Note the use of single quotes to delimit a string containing # double quotes normal('"a2dd"aP') E659 The ":python" command cannot be used recursively with Python 2.2 and older. This only works with Python 2.3 and later: :py vim.command("python print 'Hello again Python'") vim.eval(str) python-eval Evaluates the expression str using the vim internal expression evaluator (see expression). Returns the expression result as: - a string if the Vim expression evaluates to a string or number - a list if the Vim expression evaluates to a Vim list - a dictionary if the Vim expression evaluates to a Vim dictionary Dictionaries and lists are recursively expanded. Examples: :py text_width = vim.eval("&tw") :py str = vim.eval("12+12") # NB result is a string! Use # string.atoi() to convert to # a number. :py tagList = vim.eval('taglist("eval_expr")') The latter will return a python list of python dicts, for instance: [{'cmd': '/^eval_expr(arg, nextcmd)$/', 'static': 0, 'name': 'eval_expr', 'kind': 'f', 'filename': './src/eval.c'}] vim.bindeval(str) python-bindeval Like python-eval, but returns special objects described in python-bindeval-objects. These python objects let you modify (List or Dictionary) or call (Funcref) vim objects. vim.strwidth(str) python-strwidth Like strwidth(): returns number of display cells str occupies, tab is counted as one cell. vim.foreach_rtp(callable) python-foreach_rtp Call the given callable for each path in 'runtimepath' until either callable returns something but None, the exception is raised or there are no longer paths. If stopped in case callable returned non-None, vim.foreach_rtp function returns the value returned by callable. vim.chdir(*args, **kwargs) python-chdir vim.fchdir(*args, **kwargs) python-fchdir Run os.chdir or os.fchdir, then all appropriate vim stuff. Note: you should not use these functions directly, use os.chdir and os.fchdir instead. Behavior of vim.fchdir is undefined in case os.fchdir does not exist. Error object of the "vim" module vim.error python-error Upon encountering a Vim error, Python raises an exception of type vim.error. Example: try: vim.command("put a") except vim.error: # nothing in register a Constants of the "vim" module Note that these are not actually constants - you could reassign them. But this is silly, as you would then lose access to the vim objects to which the variables referred. vim.buffers python-buffers A mapping object providing access to the list of vim buffers. The object supports the following operations: :py b = vim.buffers[i] # Indexing (read-only) :py b in vim.buffers # Membership test :py n = len(vim.buffers) # Number of elements :py for b in vim.buffers: # Iterating over buffer list vim.windows python-windows A sequence object providing access to the list of vim windows. The object supports the following operations: :py w = vim.windows[i] # Indexing (read-only) :py w in vim.windows # Membership test :py n = len(vim.windows) # Number of elements :py for w in vim.windows: # Sequential access Note: vim.windows object always accesses current tab page. python-tabpage.windows objects are bound to parent python-tabpage object and always use windows from that tab page (or throw vim.error in case tab page was deleted). You can keep a reference to both without keeping a reference to vim module object or python-tabpage, they will not lose their properties in this case. vim.tabpages python-tabpages A sequence object providing access to the list of vim tab pages. The object supports the following operations: :py t = vim.tabpages[i] # Indexing (read-only) :py t in vim.tabpages # Membership test :py n = len(vim.tabpages) # Number of elements :py for t in vim.tabpages: # Sequential access vim.current python-current An object providing access (via specific attributes) to various "current" objects available in vim: vim.current.line The current line (RW) String vim.current.buffer The current buffer (RW) Buffer vim.current.window The current window (RW) Window vim.current.tabpage The current tab page (RW) TabPage vim.current.range The current line range (RO) Range The last case deserves a little explanation. When the :python or :pyfile command specifies a range, this range of lines becomes the "current range". A range is a bit like a buffer, but with all access restricted to a subset of lines. See python-range for more details. Note: When assigning to vim.current.{buffer,window,tabpage} it expects valid python-buffer, python-window or python-tabpage objects respectively. Assigning triggers normal (with autocommands) switching to given buffer, window or tab page. It is the only way to switch UI objects in python: you can't assign to python-tabpage.window attribute. To switch without triggering autocommands use py << EOF saved_eventignore = vim.options['eventignore'] vim.options['eventignore'] = 'all' try: vim.current.buffer = vim.buffers[2] # Switch to buffer 2 finally: vim.options['eventignore'] = saved_eventignore EOF vim.vars python-vars vim.vvars python-vvars Dictionary-like objects holding dictionaries with global (g:) and vim (v:) variables respectively. Identical to vim.bindeval("g:"), but faster. vim.options python-options Object partly supporting mapping protocol (supports setting and getting items) providing a read-write access to global options. Note: unlike :set this provides access only to global options. You cannot use this object to obtain or set local options' values or access local-only options in any fashion. Raises KeyError if no global option with such name exists (i.e. does not raise KeyError for global-local options and global only options, but does for window- and buffer-local ones). Use python-buffer objects to access to buffer-local options and python-window objects to access to window-local options. Type of this object is available via "Options" attribute of vim module. Output from Python python-output Vim displays all Python code output in the Vim message area. Normal output appears as information messages, and error output appears as error messages. In implementation terms, this means that all output to sys.stdout (including the output from print statements) appears as information messages, and all output to sys.stderr (including error tracebacks) appears as error messages. python-input Input (via sys.stdin, including input() and raw_input()) is not supported, and may cause the program to crash. This should probably be fixed. python2-directory python3-directory pythonx-directory Python 'runtimepath' handling python-special-path In python vim.VIM_SPECIAL_PATH special directory is used as a replacement for the list of paths found in 'runtimepath': with this directory in sys.path and vim.path_hooks in sys.path_hooks python will try to load module from {rtp}/python2 (or python3) and {rtp}/pythonx (for both python versions) for each {rtp} found in 'runtimepath'. Implementation is similar to the following, but written in C: from imp import find_module, load_module import vim import sys class VimModuleLoader(object): def __init__(self, module): self.module = module def load_module(self, fullname, path=None): return self.module def _find_module(fullname, oldtail, path): idx = oldtail.find('.') if idx > 0: name = oldtail[:idx] tail = oldtail[idx+1:] fmr = find_module(name, path) module = load_module(fullname[:-len(oldtail)] + name, *fmr) return _find_module(fullname, tail, module.__path__) else: fmr = find_module(fullname, path) return load_module(fullname, *fmr) # It uses vim module itself in place of VimPathFinder class: it does not # matter for python which object has find_module function attached to as # an attribute. class VimPathFinder(object): @classmethod def find_module(cls, fullname, path=None): try: return VimModuleLoader(_find_module(fullname, fullname, path or vim._get_paths())) except ImportError: return None @classmethod def load_module(cls, fullname, path=None): return _find_module(fullname, fullname, path or vim._get_paths()) def hook(path): if path == vim.VIM_SPECIAL_PATH: return VimPathFinder else: raise ImportError sys.path_hooks.append(hook) vim.VIM_SPECIAL_PATH python-VIM_SPECIAL_PATH String constant used in conjunction with vim path hook. If path hook installed by vim is requested to handle anything but path equal to vim.VIM_SPECIAL_PATH constant it raises ImportError. In the only other case it uses special loader. Note: you must not use value of this constant directly, always use vim.VIM_SPECIAL_PATH object. vim.find_module(...) python-find_module vim.path_hook(path) python-path_hook Methods or objects used to implement path loading as described above. You should not be using any of these directly except for vim.path_hook in case you need to do something with sys.meta_path. It is not guaranteed that any of the objects will exist in the future vim versions. vim._get_paths python-_get_paths Methods returning a list of paths which will be searched for by path hook. You should not rely on this method being present in future versions, but can use it for debugging. It returns a list of {rtp}/python2 (or {rtp}/python3) and {rtp}/pythonx directories for each {rtp} in 'runtimepath'. ============================================================================== 3. Buffer objects python-buffer Buffer objects represent vim buffers. You can obtain them in a number of ways: - via vim.current.buffer (python-current) - from indexing vim.buffers (python-buffers) - from the "buffer" attribute of a window (python-window) Buffer objects have two read-only attributes - name - the full file name for the buffer, and number - the buffer number. They also have three methods (append, mark, and range; see below). You can also treat buffer objects as sequence objects. In this context, they act as if they were lists (yes, they are mutable) of strings, with each element being a line of the buffer. All of the usual sequence operations, including indexing, index assignment, slicing and slice assignment, work as you would expect. Note that the result of indexing (slicing) a buffer is a string (list of strings). This has one unusual consequence - b[:] is different from b. In particular, "b[:] = None" deletes the whole of the buffer, whereas "b = None" merely updates the variable b, with no effect on the buffer. Buffer indexes start at zero, as is normal in Python. This differs from vim line numbers, which start from 1. This is particularly relevant when dealing with marks (see below) which use vim line numbers. The buffer object attributes are: b.vars Dictionary-like object used to access buffer-variables. b.options Mapping object (supports item getting, setting and deleting) that provides access to buffer-local options and buffer-local values of global-local options. Use python-window.options if option is window-local, this object will raise KeyError. If option is global-local and local value is missing getting it will return None. b.name String, RW. Contains buffer name (full path). Note: when assigning to b.name BufFilePre and BufFilePost autocommands are launched. b.number Buffer number. Can be used as python-buffers key. Read-only. b.valid True or False. Buffer object becomes invalid when corresponding buffer is wiped out. The buffer object methods are: b.append(str) Append a line to the buffer b.append(str, nr) Idem, below line "nr" b.append(list) Append a list of lines to the buffer Note that the option of supplying a list of strings to the append method differs from the equivalent method for Python's built-in list objects. b.append(list, nr) Idem, below line "nr" b.mark(name) Return a tuple (row,col) representing the position of the named mark (can also get the []"<> marks) b.range(s,e) Return a range object (see python-range) which represents the part of the given buffer between line numbers s and e inclusive. Note that when adding a line it must not contain a line break character '\n'. A trailing '\n' is allowed and ignored, so that you can do: :py b.append(f.readlines()) Buffer object type is available using "Buffer" attribute of vim module. Examples (assume b is the current buffer) :py print b.name # write the buffer file name :py b[0] = "hello!!!" # replace the top line :py b[:] = None # delete the whole buffer :py del b[:] # delete the whole buffer :py b[0:0] = [ "a line" ] # add a line at the top :py del b[2] # delete a line (the third) :py b.append("bottom") # add a line at the bottom :py n = len(b) # number of lines :py (row,col) = b.mark('a') # named mark :py r = b.range(1,5) # a sub-range of the buffer :py b.vars["foo"] = "bar" # assign b:foo variable :py b.options["ff"] = "dos" # set fileformat :py del b.options["ar"] # same as :set autoread< ============================================================================== 4. Range objects python-range Range objects represent a part of a vim buffer. You can obtain them in a number of ways: - via vim.current.range (python-current) - from a buffer's range() method (python-buffer) A range object is almost identical in operation to a buffer object. However, all operations are restricted to the lines within the range (this line range can, of course, change as a result of slice assignments, line deletions, or the range.append() method). The range object attributes are: r.start Index of first line into the buffer r.end Index of last line into the buffer The range object methods are: r.append(str) Append a line to the range r.append(str, nr) Idem, after line "nr" r.append(list) Append a list of lines to the range Note that the option of supplying a list of strings to the append method differs from the equivalent method for Python's built-in list objects. r.append(list, nr) Idem, after line "nr" Range object type is available using "Range" attribute of vim module. Example (assume r is the current range): # Send all lines in a range to the default printer vim.command("%d,%dhardcopy!" % (r.start+1,r.end+1)) ============================================================================== 5. Window objects python-window Window objects represent vim windows. You can obtain them in a number of ways: - via vim.current.window (python-current) - from indexing vim.windows (python-windows) - from indexing "windows" attribute of a tab page (python-tabpage) - from the "window" attribute of a tab page (python-tabpage) You can manipulate window objects only through their attributes. They have no methods, and no sequence or other interface. Window attributes are: buffer (read-only) The buffer displayed in this window cursor (read-write) The current cursor position in the window This is a tuple, (row,col). height (read-write) The window height, in rows width (read-write) The window width, in columns vars (read-only) The window w: variables. Attribute is unassignable, but you can change window variables this way options (read-only) The window-local options. Attribute is unassignable, but you can change window options this way. Provides access only to window-local options, for buffer-local use python-buffer and for global ones use python-options. If option is global-local and local value is missing getting it will return None. number (read-only) Window number. The first window has number 1. This is zero in case it cannot be determined (e.g. when the window object belongs to other tab page). row, col (read-only) On-screen window position in display cells. First position is zero. tabpage (read-only) Window tab page. valid (read-write) True or False. Window object becomes invalid when corresponding window is closed. The height attribute is writable only if the screen is split horizontally. The width attribute is writable only if the screen is split vertically. Window object type is available using "Window" attribute of vim module. ============================================================================== 6. Tab page objects python-tabpage Tab page objects represent vim tab pages. You can obtain them in a number of ways: - via vim.current.tabpage (python-current) - from indexing vim.tabpages (python-tabpages) You can use this object to access tab page windows. They have no methods and no sequence or other interfaces. Tab page attributes are: number The tab page number like the one returned by tabpagenr(). windows Like python-windows, but for current tab page. vars The tab page t: variables. window Current tabpage window. valid True or False. Tab page object becomes invalid when corresponding tab page is closed. TabPage object type is available using "TabPage" attribute of vim module. ============================================================================== 7. vim.bindeval objects python-bindeval-objects vim.Dictionary object python-Dictionary Dictionary-like object providing access to vim Dictionary type. Attributes: Attribute Description locked One of python-.locked Value Description zero Variable is not locked vim.VAR_LOCKED Variable is locked, but can be unlocked vim.VAR_FIXED Variable is locked and can't be unlocked Read-write. You can unlock locked variable by assigning True or False to this attribute. No recursive locking is supported. scope One of Value Description zero Dictionary is not a scope one vim.VAR_DEF_SCOPE g: or l: dictionary vim.VAR_SCOPE Other scope dictionary, see internal-variables Methods (note: methods do not support keyword arguments): Method Description keys() Returns a list with dictionary keys. values() Returns a list with dictionary values. items() Returns a list of 2-tuples with dictionary contents. update(iterable), update(dictionary), update(**kwargs) Adds keys to dictionary. get(key[, default=None]) Obtain key from dictionary, returning the default if it is not present. pop(key[, default]) Remove specified key from dictionary and return corresponding value. If key is not found and default is given returns the default, otherwise raises KeyError. popitem() Remove random key from dictionary and return (key, value) pair. has_key(key) Check whether dictionary contains specified key, similar to `key in dict`. __new__(), __new__(iterable), __new__(dictionary), __new__(update) You can use vim.Dictionary() to create new vim dictionaries. d=vim.Dictionary(arg) is the same as d=vim.bindeval('{}');d.update(arg). Without arguments constructs empty dictionary. Examples: d = vim.Dictionary(food="bar") # Constructor d['a'] = 'b' # Item assignment print d['a'] # getting item d.update({'c': 'd'}) # .update(dictionary) d.update(e='f') # .update(**kwargs) d.update((('g', 'h'), ('i', 'j'))) # .update(iterable) for key in d.keys(): # .keys() for val in d.values(): # .values() for key, val in d.items(): # .items() print isinstance(d, vim.Dictionary) # True for key in d: # Iteration over keys class Dict(vim.Dictionary): # Subclassing Note: when iterating over keys you should not modify dictionary. vim.List object python-List Sequence-like object providing access to vim List type. Supports .locked attribute, see python-.locked. Also supports the following methods: Method Description extend(item) Add items to the list. __new__(), __new__(iterable) You can use vim.List() to create new vim lists. l=vim.List(iterable) is the same as l=vim.bindeval('[]');l.extend(iterable). Without arguments constructs empty list. Examples: l = vim.List("abc") # Constructor, result: ['a', 'b', 'c'] l.extend(['abc', 'def']) # .extend() method print l[1:] # slicing l[:0] = ['ghi', 'jkl'] # slice assignment print l[0] # getting item l[0] = 'mno' # assignment for i in l: # iteration print isinstance(l, vim.List) # True class List(vim.List): # Subclassing vim.Function object python-Function Function-like object, acting like vim Funcref object. Accepts special keyword argument self, see Dictionary-function. You can also use vim.Function(name) constructor, it is the same as vim.bindeval('function(%s)'%json.dumps(name)). Attributes (read-only): Attribute Description name Function name. args None or a python-List object with arguments. Note that this is a copy of the arguments list, constructed each time you request this attribute. Modifications made to the list will be ignored (but not to the containers inside argument list: this is like copy() and not deepcopy()). self None or a python-Dictionary object with self dictionary. Note that explicit self keyword used when calling resulting object overrides this attribute. Constructor additionally accepts args and self keywords. If any of them is given then it constructs a partial, see function(). Examples: f = vim.Function('tr') # Constructor print f('abc', 'a', 'b') # Calls tr('abc', 'a', 'b') vim.command(''' function DictFun() dict return self endfunction ''') f = vim.bindeval('function("DictFun")') print f(self={}) # Like call('DictFun', [], {}) print isinstance(f, vim.Function) # True p = vim.Function('DictFun', self={}) print f() p = vim.Function('tr', args=['abc', 'a']) print f('b') ============================================================================== 8. pyeval() and py3eval() Vim functions python-pyeval To facilitate bi-directional interface, you can use pyeval() and py3eval() functions to evaluate Python expressions and pass their values to VimL. ============================================================================== 9. Dynamic loading python-dynamic On MS-Windows and Unix the Python library can be loaded dynamically. The :version output then includes +python/dyn or +python3/dyn. This means that Vim will search for the Python DLL or shared library file only when needed. When you don't use the Python interface you don't need it, thus you can use Vim without this file. MS-Windows To use the Python interface the Python DLL must be in your search path. In a console window type "path" to see what directories are used. The 'pythondll' or 'pythonthreedll' option can be also used to specify the Python DLL. The name of the DLL must match the Python version Vim was compiled with. Currently the name is "python24.dll". That is for Python 2.4. To know for sure edit "gvim.exe" and search for "python\d*.dll\c". Unix The 'pythondll' or 'pythonthreedll' option can be used to specify the Python shared library file instead of DYNAMIC_PYTHON_DLL or DYNAMIC_PYTHON3_DLL file what were specified at compile time. The version of the shared library must match the Python 2.x or Python 3 version Vim was compiled with. ============================================================================== 10. Python 3 python3 :py3 :python3 The :py3 and :python3 commands work similar to :python. A simple check if the :py3 command is working: :py3 print("Hello") :py3file The :py3file command works similar to :pyfile. :py3do E863 The :py3do command works similar to :pydo. Vim can be built in four ways (:version output): 1. No Python support (-python, -python3) 2. Python 2 support only (+python or +python/dyn, -python3) 3. Python 3 support only (-python, +python3 or +python3/dyn) 4. Python 2 and 3 support (+python/dyn, +python3/dyn) Some more details on the special case 4: python-2-and-3 When Python 2 and Python 3 are both supported they must be loaded dynamically. When doing this on Linux/Unix systems and importing global symbols, this leads to a crash when the second Python version is used. So either global symbols are loaded but only one Python version is activated, or no global symbols are loaded. The latter makes Python's "import" fail on libraries that expect the symbols to be provided by Vim. E836 E837 Vim's configuration script makes a guess for all libraries based on one standard Python library (termios). If importing this library succeeds for both Python versions, then both will be made available in Vim at the same time. If not, only the version first used in a session will be enabled. When trying to use the other one you will get the E836 or E837 error message. Here Vim's behavior depends on the system in which it was configured. In a system where both versions of Python were configured with --enable-shared, both versions of Python will be activated at the same time. There will still be problems with other third party libraries that were not linked to libPython. To work around such problems there are these options: 1. The problematic library is recompiled to link to the according libpython.so. 2. Vim is recompiled for only one Python version. 3. You undefine PY_NO_RTLD_GLOBAL in auto/config.h after configuration. This may crash Vim though. E880 Raising SystemExit exception in python isn't endorsed way to quit vim, use: :py vim.command("qall!") has-python You can test what Python version is available with: if has('python') echo 'there is Python 2.x' elseif has('python3') echo 'there is Python 3.x' endif Note however, that when Python 2 and 3 are both available and loaded dynamically, these has() calls will try to load them. If only one can be loaded at a time, just checking if Python 2 or 3 are available will prevent the other one from being available. ============================================================================== vim:tw=78:ts=8:ft=help:norl:
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