This document covers all stable modules in django.utils
. Most of the
modules in django.utils
are designed for internal use and only the
following parts can be considered stable and thus backwards compatible as per
the internal release deprecation policy.
django.utils.cache
¶This module contains helper functions for controlling caching. It does so by
managing the Vary
header of responses. It includes functions to patch the
header of response objects directly and decorators that change functions to do
that header-patching themselves.
For information on the Vary
header, see RFC 7231#section-7.1.4.
Essentially, the Vary
HTTP header defines which headers a cache should take
into account when building its cache key. Requests with the same path but
different header content for headers named in Vary
need to get different
cache keys to prevent delivery of wrong content.
For example, internationalization middleware would
need to distinguish caches by the Accept-language
header.
patch_cache_control
(response, **kwargs)[source]¶This function patches the Cache-Control
header by adding all keyword
arguments to it. The transformation is as follows:
True
(exactly True
, not just a
true value), only the parameter name is added to the header.str()
to it.get_max_age
(response)[source]¶Returns the max-age from the response Cache-Control header as an integer
(or None
if it wasn’t found or wasn’t an integer).
patch_response_headers
(response, cache_timeout=None)[source]¶Adds some useful headers to the given HttpResponse
object:
ETag
Last-Modified
Expires
Cache-Control
Each header is only added if it isn’t already set.
cache_timeout
is in seconds. The CACHE_MIDDLEWARE_SECONDS
setting is used by default.
add_never_cache_headers
(response)[source]¶Adds a Cache-Control: max-age=0, no-cache, no-store, must-revalidate
header to a response to indicate that a page should never be cached.
In older versions, Cache-Control: max-age=0
was sent. This didn’t
reliably prevent caching in all browsers.
patch_vary_headers
(response, newheaders)[source]¶Adds (or updates) the Vary
header in the given HttpResponse
object.
newheaders
is a list of header names that should be in Vary
.
Existing headers in Vary
aren’t removed.
get_cache_key
(request, key_prefix=None)[source]¶Returns a cache key based on the request path. It can be used in the request phase because it pulls the list of headers to take into account from the global path registry and uses those to build a cache key to check against.
If there is no headerlist stored, the page needs to be rebuilt, so this
function returns None
.
learn_cache_key
(request, response, cache_timeout=None, key_prefix=None)[source]¶Learns what headers to take into account for some request path from the
response object. It stores those headers in a global path registry so that
later access to that path will know what headers to take into account
without building the response object itself. The headers are named in
the Vary
header of the response, but we want to prevent response
generation.
The list of headers to use for cache key generation is stored in the same cache as the pages themselves. If the cache ages some data out of the cache, this just means that we have to build the response once to get at the Vary header and so at the list of headers to use for the cache key.
django.utils.dateparse
¶The functions defined in this module share the following properties:
ValueError
if their input is well formatted but isn’t a
valid date or time.None
if it isn’t well formatted at all.parse_date
(value)[source]¶Parses a string and returns a datetime.date
.
parse_time
(value)[source]¶Parses a string and returns a datetime.time
.
UTC offsets aren’t supported; if value
describes one, the result is
None
.
parse_datetime
(value)[source]¶Parses a string and returns a datetime.datetime
.
UTC offsets are supported; if value
describes one, the result’s
tzinfo
attribute is a FixedOffset
instance.
parse_duration
(value)[source]¶Parses a string and returns a datetime.timedelta
.
Expects data in the format "DD HH:MM:SS.uuuuuu"
or as specified by ISO
8601 (e.g. P4DT1H15M20S
which is equivalent to 4 1:15:20
).
django.utils.decorators
¶method_decorator
(decorator, name=”)[source]¶Converts a function decorator into a method decorator. It can be used to
decorate methods or classes; in the latter case, name
is the name
of the method to be decorated and is required.
decorator
may also be a list or tuple of functions. They are wrapped
in reverse order so that the call order is the order in which the functions
appear in the list/tuple.
See decorating class based views for example usage.
The ability to decorate classes, the name
parameter, and the ability
for decorator
to accept a list/tuple of decorator functions were
added.
decorator_from_middleware
(middleware_class)[source]¶Given a middleware class, returns a view decorator. This lets you use middleware functionality on a per-view basis. The middleware is created with no params passed.
It assumes middleware that’s compatible with the old style of Django 1.9
and earlier (having methods like process_request()
,
process_exception()
, and process_response()
).
decorator_from_middleware_with_args
(middleware_class)[source]¶Like decorator_from_middleware
, but returns a function
that accepts the arguments to be passed to the middleware_class.
For example, the cache_page()
decorator is created from the CacheMiddleware
like this:
cache_page = decorator_from_middleware_with_args(CacheMiddleware)
@cache_page(3600)
def my_view(request):
pass
django.utils.encoding
¶python_2_unicode_compatible
()[source]¶A decorator that defines __unicode__
and __str__
methods under
Python 2. Under Python 3 it does nothing.
To support Python 2 and 3 with a single code base, define a __str__
method returning text and apply this decorator to the class.
smart_text
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)[source]¶Returns a text object representing s
– unicode
on Python 2 and
str
on Python 3. Treats bytestrings using the encoding
codec.
If strings_only
is True
, don’t convert (some) non-string-like
objects.
smart_unicode
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)¶Historical name of smart_text()
. Only available under Python 2.
is_protected_type
(obj)[source]¶Determine if the object instance is of a protected type.
Objects of protected types are preserved as-is when passed to
force_text(strings_only=True)
.
force_text
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)[source]¶Similar to smart_text
, except that lazy instances are resolved to
strings, rather than kept as lazy objects.
If strings_only
is True
, don’t convert (some) non-string-like
objects.
force_unicode
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)¶Historical name of force_text()
. Only available under Python 2.
smart_bytes
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)[source]¶Returns a bytestring version of s
, encoded as specified in
encoding
.
If strings_only
is True
, don’t convert (some) non-string-like
objects.
force_bytes
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)[source]¶Similar to smart_bytes
, except that lazy instances are resolved to
bytestrings, rather than kept as lazy objects.
If strings_only
is True
, don’t convert (some) non-string-like
objects.
smart_str
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)¶Alias of smart_bytes()
on Python 2 and smart_text()
on Python
3. This function returns a str
or a lazy string.
For instance, this is suitable for writing to sys.stdout
on
Python 2 and 3.
force_str
(s, encoding=’utf-8’, strings_only=False, errors=’strict’)¶Alias of force_bytes()
on Python 2 and force_text()
on Python
3. This function always returns a str
.
iri_to_uri
(iri)[source]¶Convert an Internationalized Resource Identifier (IRI) portion to a URI portion that is suitable for inclusion in a URL.
This is the algorithm from section 3.1 of RFC 3987#section-3.1. However, since we are assuming input is either UTF-8 or unicode already, we can simplify things a little from the full method.
Takes an IRI in UTF-8 bytes and returns ASCII bytes containing the encoded result.
uri_to_iri
(uri)[source]¶Converts a Uniform Resource Identifier into an Internationalized Resource Identifier.
This is an algorithm from section 3.2 of RFC 3987#section-3.2.
Takes a URI in ASCII bytes and returns a unicode string containing the encoded result.
filepath_to_uri
(path)[source]¶Convert a file system path to a URI portion that is suitable for inclusion in a URL. The path is assumed to be either UTF-8 or unicode.
This method will encode certain characters that would normally be
recognized as special characters for URIs. Note that this method does not
encode the ‘ character, as it is a valid character within URIs. See
encodeURIComponent()
JavaScript function for more details.
Returns an ASCII string containing the encoded result.
django.utils.feedgenerator
¶Sample usage:
>>> from django.utils import feedgenerator
>>> feed = feedgenerator.Rss201rev2Feed(
... title="Poynter E-Media Tidbits",
... link="http://www.poynter.org/column.asp?id=31",
... description="A group Weblog by the sharpest minds in online media/journalism/publishing.",
... language="en",
... )
>>> feed.add_item(
... title="Hello",
... link="http://www.holovaty.com/test/",
... description="Testing.",
... )
>>> with open('test.rss', 'w') as fp:
... feed.write(fp, 'utf-8')
For simplifying the selection of a generator use feedgenerator.DefaultFeed
which is currently Rss201rev2Feed
For definitions of the different versions of RSS, see: https://web.archive.org/web/20110718035220/http://diveintomark.org/archives/2004/02/04/incompatible-rss
get_tag_uri
(url, date)[source]¶Creates a TagURI.
See https://web.archive.org/web/20110514113830/http://diveintomark.org/archives/2004/05/28/howto-atom-id
SyndicationFeed
¶SyndicationFeed
[source]¶Base class for all syndication feeds. Subclasses should provide write().
__init__
(title, link, description, language=None, author_email=None, author_name=None, author_link=None, subtitle=None, categories=None, feed_url=None, feed_copyright=None, feed_guid=None, ttl=None, **kwargs)[source]¶Initialize the feed with the given dictionary of metadata, which applies to the entire feed.
Any extra keyword arguments you pass to __init__
will be stored in
self.feed
.
All parameters should be Unicode objects, except categories
, which
should be a sequence of Unicode objects.
add_item
(title, link, description, author_email=None, author_name=None, author_link=None, pubdate=None, comments=None, unique_id=None, enclosure=None, categories=(), item_copyright=None, ttl=None, updateddate=None, enclosures=None, **kwargs)[source]¶Adds an item to the feed. All args are expected to be Python unicode
objects except pubdate
and updateddate
, which are datetime.datetime
objects, enclosure
, which is an Enclosure
instance, and
enclosures
, which is a list of Enclosure
instances.
Deprecated since version 1.9: The enclosure
keyword argument is deprecated in favor of the
new enclosures
keyword argument which accepts a list of
Enclosure
objects.
root_attributes
()[source]¶Return extra attributes to place on the root (i.e. feed/channel)
element. Called from write()
.
add_root_elements
(handler)[source]¶Add elements in the root (i.e. feed/channel) element.
Called from write()
.
item_attributes
(item)[source]¶Return extra attributes to place on each item (i.e. item/entry) element.
django.utils.functional
¶cached_property
(object, name)[source]¶The @cached_property
decorator caches the result of a method with a
single self
argument as a property. The cached result will persist
as long as the instance does, so if the instance is passed around and the
function subsequently invoked, the cached result will be returned.
Consider a typical case, where a view might need to call a model’s method to perform some computation, before placing the model instance into the context, where the template might invoke the method once more:
# the model
class Person(models.Model):
def friends(self):
# expensive computation
...
return friends
# in the view:
if person.friends():
...
And in the template you would have:
{% for friend in person.friends %}
Here, friends()
will be called twice. Since the instance person
in
the view and the template are the same, @cached_property
can avoid
that:
from django.utils.functional import cached_property
@cached_property
def friends(self):
# expensive computation
...
return friends
Note that as the method is now a property, in Python code it will need to be invoked appropriately:
# in the view:
if person.friends:
...
The cached value can be treated like an ordinary attribute of the instance:
# clear it, requiring re-computation next time it's called
del person.friends # or delattr(person, "friends")
# set a value manually, that will persist on the instance until cleared
person.friends = ["Huckleberry Finn", "Tom Sawyer"]
As well as offering potential performance advantages, @cached_property
can ensure that an attribute’s value does not change unexpectedly over the
life of an instance. This could occur with a method whose computation is
based on datetime.now()
, or simply if a change were saved to the
database by some other process in the brief interval between subsequent
invocations of a method on the same instance.
You can use the name
argument to make cached properties of other
methods. For example, if you had an expensive get_friends()
method and
wanted to allow calling it without retrieving the cached value, you could
write:
friends = cached_property(get_friends, name='friends')
While person.get_friends()
will recompute the friends on each call, the
value of the cached property will persist until you delete it as described
above:
x = person.friends # calls first time
y = person.get_friends() # calls again
z = person.friends # does not call
x is z # is True
allow_lazy
(func, *resultclasses)[source]¶Deprecated since version 1.10.
Works like keep_lazy()
except that it can’t
be used as a decorator.
keep_lazy
(func, *resultclasses)[source]¶Django offers many utility functions (particularly in django.utils
)
that take a string as their first argument and do something to that string.
These functions are used by template filters as well as directly in other
code.
If you write your own similar functions and deal with translations, you’ll face the problem of what to do when the first argument is a lazy translation object. You don’t want to convert it to a string immediately, because you might be using this function outside of a view (and hence the current thread’s locale setting will not be correct).
For cases like this, use the django.utils.functional.keep_lazy()
decorator. It modifies the function so that if it’s called with a lazy
translation as one of its arguments, the function evaluation is delayed
until it needs to be converted to a string.
For example:
from django.utils import six
from django.utils.functional import keep_lazy, keep_lazy_text
def fancy_utility_function(s, ...):
# Do some conversion on string 's'
...
fancy_utility_function = keep_lazy(six.text_type)(fancy_utility_function)
# Or more succinctly:
@keep_lazy(six.text_type)
def fancy_utility_function(s, ...):
...
The keep_lazy()
decorator takes a number of extra arguments (*args
)
specifying the type(s) that the original function can return. A common
use case is to have functions that return text. For these, you can just
pass the six.text_type
type to keep_lazy
(or even simpler, use the
keep_lazy_text()
decorator described in the next section).
Using this decorator means you can write your function and assume that the input is a proper string, then add support for lazy translation objects at the end.
keep_lazy_text
(func)[source]¶A shortcut for keep_lazy(six.text_type)(func)
.
If you have a function that returns text and you want to be able to take lazy arguments while delaying their evaluation, simply use this decorator:
from django.utils import six
from django.utils.functional import keep_lazy, keep_lazy_text
# Our previous example was:
@keep_lazy(six.text_type)
def fancy_utility_function(s, ...):
...
# Which can be rewritten as:
@keep_lazy_text
def fancy_utility_function(s, ...):
...
django.utils.html
¶Usually you should build up HTML using Django’s templates to make use of its
autoescape mechanism, using the utilities in django.utils.safestring
where appropriate. This module provides some additional low level utilities for
escaping HTML.
escape
(text)[source]¶Returns the given text with ampersands, quotes and angle brackets encoded
for use in HTML. The input is first passed through
force_text()
and the output has
mark_safe()
applied.
conditional_escape
(text)[source]¶Similar to escape()
, except that it doesn’t operate on pre-escaped
strings, so it will not double escape.
format_html
(format_string, *args, **kwargs)[source]¶This is similar to str.format()
, except that it is appropriate for
building up HTML fragments. All args and kwargs are passed through
conditional_escape()
before being passed to str.format()
.
For the case of building up small HTML fragments, this function is to be
preferred over string interpolation using %
or str.format()
directly, because it applies escaping to all arguments - just like the
template system applies escaping by default.
So, instead of writing:
mark_safe("%s <b>%s</b> %s" % (
some_html,
escape(some_text),
escape(some_other_text),
))
You should instead use:
format_html("{} <b>{}</b> {}",
mark_safe(some_html),
some_text,
some_other_text,
)
This has the advantage that you don’t need to apply escape()
to each
argument and risk a bug and an XSS vulnerability if you forget one.
Note that although this function uses str.format()
to do the
interpolation, some of the formatting options provided by str.format()
(e.g. number formatting) will not work, since all arguments are passed
through conditional_escape()
which (ultimately) calls
force_text()
on the values.
format_html_join
(sep, format_string, args_generator)[source]¶A wrapper of format_html()
, for the common case of a group of
arguments that need to be formatted using the same format string, and then
joined using sep
. sep
is also passed through
conditional_escape()
.
args_generator
should be an iterator that returns the sequence of
args
that will be passed to format_html()
. For example:
format_html_join(
'\n', "<li>{} {}</li>",
((u.first_name, u.last_name) for u in users)
)
Tries to remove anything that looks like an HTML tag from the string, that
is anything contained within <>
.
Absolutely NO guarantee is provided about the resulting string being
HTML safe. So NEVER mark safe the result of a strip_tag
call without
escaping it first, for example with escape()
.
For example:
strip_tags(value)
If value
is "<b>Joel</b> <button>is</button> a <span>slug</span>"
the return value will be "Joel is a slug"
.
If you are looking for a more robust solution, take a look at the bleach Python library.
html_safe
()[source]¶The __html__()
method on a class helps non-Django templates detect
classes whose output doesn’t require HTML escaping.
This decorator defines the __html__()
method on the decorated class
by wrapping the __unicode__()
(Python 2) or __str__()
(Python 3)
in mark_safe()
. Ensure the __unicode__()
or __str__()
method does indeed return text that doesn’t require HTML
escaping.
django.utils.http
¶urlquote
(url, safe=’/’)[source]¶A version of Python’s urllib.quote()
function that can operate on
unicode strings. The url is first UTF-8 encoded before quoting. The
returned string can safely be used as part of an argument to a subsequent
iri_to_uri()
call without double-quoting occurring. Employs lazy
execution.
urlquote_plus
(url, safe=”)[source]¶A version of Python’s urllib.quote_plus() function that can operate on
unicode strings. The url is first UTF-8 encoded before quoting. The
returned string can safely be used as part of an argument to a subsequent
iri_to_uri()
call without double-quoting occurring. Employs lazy
execution.
urlencode
(query, doseq=0)[source]¶A version of Python’s urllib.urlencode() function that can operate on unicode strings. The parameters are first cast to UTF-8 encoded strings and then encoded as per normal.
Formats the time to ensure compatibility with Netscape’s cookie standard.
Accepts a floating point number expressed in seconds since the epoch in
UTC–such as that outputted by time.time()
. If set to None
,
defaults to the current time.
Outputs a string in the format Wdy, DD-Mon-YYYY HH:MM:SS GMT
.
http_date
(epoch_seconds=None)[source]¶Formats the time to match the RFC 1123 date format as specified by HTTP RFC 7231#section-7.1.1.1.
Accepts a floating point number expressed in seconds since the epoch in
UTC–such as that outputted by time.time()
. If set to None
,
defaults to the current time.
Outputs a string in the format Wdy, DD Mon YYYY HH:MM:SS GMT
.
base36_to_int
(s)[source]¶Converts a base 36 string to an integer. On Python 2 the output is
guaranteed to be an int
and not a long
.
int_to_base36
(i)[source]¶Converts a positive integer to a base 36 string. On Python 2 i
must be
smaller than sys.maxint.
django.utils.module_loading
¶Functions for working with Python modules.
import_string
(dotted_path)[source]¶Imports a dotted module path and returns the attribute/class designated by
the last name in the path. Raises ImportError
if the import failed. For
example:
from django.utils.module_loading import import_string
ValidationError = import_string('django.core.exceptions.ValidationError')
is equivalent to:
from django.core.exceptions import ValidationError
django.utils.safestring
¶Functions and classes for working with “safe strings”: strings that can be displayed safely without further escaping in HTML. Marking something as a “safe string” means that the producer of the string has already turned characters that should not be interpreted by the HTML engine (e.g. ‘<’) into the appropriate entities.
SafeBytes
[source]¶A bytes
subclass that has been specifically marked as “safe”
(requires no further escaping) for HTML output purposes.
SafeString
¶A str
subclass that has been specifically marked as “safe”
(requires no further escaping) for HTML output purposes. This is
SafeBytes
on Python 2 and SafeText
on Python 3.
SafeText
[source]¶A str
(in Python 3) or unicode
(in Python 2) subclass
that has been specifically marked as “safe” for HTML output purposes.
mark_safe
(s)[source]¶Explicitly mark a string as safe for (HTML) output purposes. The returned object can be used everywhere a string or unicode object is appropriate.
Can be called multiple times on a single string.
For building up fragments of HTML, you should normally be using
django.utils.html.format_html()
instead.
String marked safe will become unsafe again if modified. For example:
>>> mystr = '<b>Hello World</b> '
>>> mystr = mark_safe(mystr)
>>> type(mystr)
<class 'django.utils.safestring.SafeBytes'>
>>> mystr = mystr.strip() # removing whitespace
>>> type(mystr)
<type 'str'>
django.utils.text
¶slugify
(allow_unicode=False)[source]¶Converts to ASCII if allow_unicode
is False
(default). Converts spaces to
hyphens. Removes characters that aren’t alphanumerics, underscores, or
hyphens. Converts to lowercase. Also strips leading and trailing whitespace.
For example:
slugify(value)
If value
is "Joel is a slug"
, the output will be
"joel-is-a-slug"
.
You can set the allow_unicode
parameter to True
, if you want to
allow Unicode characters:
slugify(value, allow_unicode=True)
If value
is "你好 World"
, the output will be "你好-world"
.
The allow_unicode
parameter was added.
django.utils.timezone
¶FixedOffset
(offset=None, name=None)[source]¶A tzinfo
subclass modeling a fixed offset from UTC.
offset
is an integer number of minutes east of UTC.
get_fixed_timezone
(offset)[source]¶Returns a tzinfo
instance that represents a time zone
with a fixed offset from UTC.
offset
is a datetime.timedelta
or an integer number of
minutes. Use positive values for time zones east of UTC and negative
values for west of UTC.
get_default_timezone
()[source]¶Returns a tzinfo
instance that represents the
default time zone.
get_default_timezone_name
()[source]¶Returns the name of the default time zone.
get_current_timezone
()[source]¶Returns a tzinfo
instance that represents the
current time zone.
get_current_timezone_name
()[source]¶Returns the name of the current time zone.
activate
(timezone)[source]¶Sets the current time zone. The
timezone
argument must be an instance of a tzinfo
subclass or, if pytz is available, a time zone name.
deactivate
()[source]¶Unsets the current time zone.
override
(timezone)[source]¶This is a Python context manager that sets the current time zone on entry with activate()
, and restores
the previously active time zone on exit. If the timezone
argument is
None
, the current time zone is unset
on entry with deactivate()
instead.
override
is also usable as a function decorator.
localtime
(value, timezone=None)[source]¶Converts an aware datetime
to a different time zone,
by default the current time zone.
This function doesn’t work on naive datetimes; use make_aware()
instead.
now
()[source]¶Returns a datetime
that represents the
current point in time. Exactly what’s returned depends on the value of
USE_TZ
:
USE_TZ
is False
, this will be a
naive datetime (i.e. a datetime
without an associated timezone) that represents the current time
in the system’s local timezone.USE_TZ
is True
, this will be an
aware datetime representing the
current time in UTC. Note that now()
will always return
times in UTC regardless of the value of TIME_ZONE
;
you can use localtime()
to convert to a time in the current
time zone.is_aware
(value)[source]¶Returns True
if value
is aware, False
if it is naive. This
function assumes that value
is a datetime
.
is_naive
(value)[source]¶Returns True
if value
is naive, False
if it is aware. This
function assumes that value
is a datetime
.
make_aware
(value, timezone=None, is_dst=None)[source]¶Returns an aware datetime
that represents the same
point in time as value
in timezone
, value
being a naive
datetime
. If timezone
is set to None
, it
defaults to the current time zone.
When pytz is installed, the exception pytz.AmbiguousTimeError
will be raised if you try to make value
aware during a DST transition
where the same time occurs twice (when reverting from DST). Setting
is_dst
to True
or False
will avoid the exception by choosing if
the time is pre-transition or post-transition respectively.
When pytz is installed, the exception pytz.NonExistentTimeError
will be raised if you try to make value
aware during a DST transition
such that the time never occurred (when entering into DST). Setting
is_dst
to True
or False
will avoid the exception by moving the
hour backwards or forwards by 1 respectively. For example, is_dst=True
would change a non-existent time of 2:30 to 1:30 and is_dst=False
would change the time to 3:30.
is_dst
has no effect when pytz
is not installed.
The is_dst
argument was added.
make_naive
(value, timezone=None)[source]¶Returns an naive datetime
that represents in
timezone
the same point in time as value
, value
being an
aware datetime
. If timezone
is set to None
, it
defaults to the current time zone.
django.utils.translation
¶For a complete discussion on the usage of the following see the translation documentation.
pgettext
(context, message)[source]¶Translates message
given the context
and returns
it in a unicode string.
For more information, see Contextual markers.
gettext_lazy
(message)¶ugettext_lazy
(message)¶pgettext_lazy
(context, message)¶Same as the non-lazy versions above, but using lazy execution.
ugettext_noop
(message)¶Marks strings for translation but doesn’t translate them now. This can be used to store strings in global variables that should stay in the base language (because they might be used externally) and will be translated later.
ngettext
(singular, plural, number)[source]¶Translates singular
and plural
and returns the appropriate string
based on number
in a UTF-8 bytestring.
ungettext
(singular, plural, number)[source]¶Translates singular
and plural
and returns the appropriate string
based on number
in a unicode string.
npgettext
(context, singular, plural, number)[source]¶Translates singular
and plural
and returns the appropriate string
based on number
and the context
in a unicode string.
npgettext_lazy
(context, singular, plural, number)[source]¶Same as the non-lazy versions above, but using lazy execution.
string_concat
(*strings)¶Lazy variant of string concatenation, needed for translations that are constructed from multiple parts.
activate
(language)[source]¶Fetches the translation object for a given language and activates it as the current translation object for the current thread.
deactivate
()[source]¶Deactivates the currently active translation object so that further _ calls will resolve against the default translation object, again.
deactivate_all
()[source]¶Makes the active translation object a NullTranslations()
instance.
This is useful when we want delayed translations to appear as the original
string for some reason.
override
(language, deactivate=False)[source]¶A Python context manager that uses
django.utils.translation.activate()
to fetch the translation object
for a given language, activates it as the translation object for the
current thread and reactivates the previous active language on exit.
Optionally, it can simply deactivate the temporary translation on exit with
django.utils.translation.deactivate()
if the deactivate
argument
is True
. If you pass None
as the language argument, a
NullTranslations()
instance is activated within the context.
override
is also usable as a function decorator.
check_for_language
(lang_code)[source]¶Checks whether there is a global language file for the given language code (e.g. ‘fr’, ‘pt_BR’). This is used to decide whether a user-provided language is available.
get_language
()[source]¶Returns the currently selected language code. Returns None
if
translations are temporarily deactivated (by deactivate_all()
or
when None
is passed to override()
).
get_language_bidi
()[source]¶Returns selected language’s BiDi layout:
False
= left-to-right layoutTrue
= right-to-left layoutget_language_from_request
(request, check_path=False)[source]¶Analyzes the request to find what language the user wants the system to show. Only languages listed in settings.LANGUAGES are taken into account. If the user requests a sublanguage where we have a main language, we send out the main language.
If check_path
is True
, the function first checks the requested URL
for whether its path begins with a language code listed in the
LANGUAGES
setting.
templatize
(src)[source]¶Turns a Django template into something that is understood by xgettext
.
It does so by translating the Django translation tags into standard
gettext
function invocations.
LANGUAGE_SESSION_KEY
¶Session key under which the active language for the current session is stored.
Jun 09, 2017