Django Utils

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)[ソース]

This function patches the Cache-Control header by adding all keyword arguments to it. The transformation is as follows:

  • All keyword parameter names are turned to lowercase, and underscores are converted to hyphens.
  • If the value of a parameter is True (exactly True, not just a true value), only the parameter name is added to the header.
  • All other parameters are added with their value, after applying str() to it.
get_max_age(response)[ソース]

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)[ソース]

Adds some useful headers to the given HttpResponse object:

  • ETag
  • 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.

Changed in Django 1.11:

In older versions, the Last-Modified header was also set.

バージョン 1.11 で撤廃: Since the USE_ETAGS setting is deprecated, this function won’t set the ETag header when the deprecation ends in Django 2.1.

add_never_cache_headers(response)[ソース]

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.

patch_vary_headers(response, newheaders)[ソース]

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)[ソース]

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)[ソース]

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:

  • They raise ValueError if their input is well formatted but isn’t a valid date or time.
  • They return None if it isn’t well formatted at all.
  • They accept up to picosecond resolution in input, but they truncate it to microseconds, since that’s what Python supports.
parse_date(value)[ソース]

Parses a string and returns a datetime.date.

parse_time(value)[ソース]

Parses a string and returns a datetime.time.

UTC offsets aren’t supported; if value describes one, the result is None.

parse_datetime(value)[ソース]

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)[ソース]

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='')[ソース]

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.

decorator_from_middleware(middleware_class)[ソース]

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)[ソース]

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()[ソース]

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 (use six.text_type() if you’re doing some casting) and apply this decorator to the class.

smart_text(s, encoding='utf-8', strings_only=False, errors='strict')[ソース]

Returns a text object representing sunicode 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)[ソース]

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')[ソース]

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')[ソース]

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')[ソース]

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)[ソース]

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)[ソース]

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)[ソース]

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.

escape_uri_path(path)[ソース]

Escapes the unsafe characters from the path portion of a Uniform Resource Identifier (URI).

django.utils.feedgenerator

使用例:

>>> 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)[ソース]

Creates a TagURI.

See https://web.archive.org/web/20110514113830/http://diveintomark.org/archives/2004/05/28/howto-atom-id

SyndicationFeed

class SyndicationFeed[ソース]

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)[ソース]

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)[ソース]

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.

バージョン 1.9 で撤廃: The enclosure keyword argument is deprecated in favor of the new enclosures keyword argument which accepts a list of Enclosure objects.

num_items()[ソース]
root_attributes()[ソース]

Return extra attributes to place on the root (i.e. feed/channel) element. Called from write().

add_root_elements(handler)[ソース]

Add elements in the root (i.e. feed/channel) element. Called from write().

item_attributes(item)[ソース]

Return extra attributes to place on each item (i.e. item/entry) element.

add_item_elements(handler, item)[ソース]

Add elements on each item (i.e. item/entry) element.

write(outfile, encoding)[ソース]

Outputs the feed in the given encoding to outfile, which is a file-like object. Subclasses should override this.

writeString(encoding)[ソース]

Returns the feed in the given encoding as a string.

latest_post_date()[ソース]

Returns the latest pubdate or updateddate for all items in the feed. If no items have either of these attributes this returns the current UTC date/time.

Changed in Django 1.11:

In older versions, it returned the current date/time without any timezone information.

Enclosure

class Enclosure[ソース]

Represents an RSS enclosure

RssFeed

class RssFeed(SyndicationFeed)[ソース]

Rss201rev2Feed

class Rss201rev2Feed(RssFeed)[ソース]

Spec: https://cyber.harvard.edu/rss/rss.html

RssUserland091Feed

class RssUserland091Feed(RssFeed)[ソース]

Spec: http://backend.userland.com/rss091

Atom1Feed

class Atom1Feed(SyndicationFeed)[ソース]

Spec: https://tools.ietf.org/html/rfc4287

django.utils.functional

class cached_property(object, name)[ソース]

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, decorating the friends() method with @cached_property can avoid that:

from django.utils.functional import cached_property

class Person(models.Model):

    @cached_property
    def friends(self):
        ...

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)[ソース]

バージョン 1.10 で撤廃.

Works like keep_lazy() except that it can’t be used as a decorator.

keep_lazy(func, *resultclasses)[ソース]
New in Django 1.10.

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)[ソース]
New in Django 1.10.

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)[ソース]

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)[ソース]

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)[ソース]

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)[ソース]

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)
)
strip_tags(value)[ソース]

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()[ソース]

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='/')[ソース]

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='')[ソース]

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)[ソース]

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.

cookie_date(epoch_seconds=None)[ソース]

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)[ソース]

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)[ソース]

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)[ソース]

Converts a positive integer to a base 36 string. On Python 2 i must be smaller than sys.maxint.

urlsafe_base64_encode(s)[ソース]

Encodes a bytestring in base64 for use in URLs, stripping any trailing equal signs.

urlsafe_base64_decode(s)[ソース]

Decodes a base64 encoded string, adding back any trailing equal signs that might have been stripped.

django.utils.module_loading

Functions for working with Python modules.

import_string(dotted_path)[ソース]

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')

これは以下と同じです:

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.

class SafeBytes[ソース]

A bytes subclass that has been specifically marked as 「safe」 (requires no further escaping) for HTML output purposes.

class 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.

class SafeText[ソース]

A str (in Python 3) or unicode (in Python 2) subclass that has been specifically marked as 「safe」 for HTML output purposes.

class SafeUnicode

Historical name of SafeText. Only available under Python 2.

mark_safe(s)[ソース]

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.

Can also be used as a decorator.

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'>
Changed in Django 1.11:

Added support for decorator usage.

mark_for_escaping(s)[ソース]

バージョン 1.10 で撤廃.

Explicitly mark a string as requiring HTML escaping upon output. Has no effect on SafeData subclasses.

Can be called multiple times on a single string (the resulting escaping is only applied once).

django.utils.text

format_lazy(format_string, *args, **kwargs)
New in Django 1.11.

A version of str.format() for when format_string, args, and/or kwargs contain lazy objects. The first argument is the string to be formatted. For example:

from django.utils.text import format_lazy
from django.utils.translation import pgettext_lazy

urlpatterns = [
    url(format_lazy(r'{person}/(?P<pk>\d+)/$', person=pgettext_lazy('URL', 'person')),
        PersonDetailView.as_view()),
]

This example allows translators to translate part of the URL. If 「person」 is translated to 「persona」, the regular expression will match persona/(?P<pk>\d+)/$, e.g. persona/5/.

slugify(allow_unicode=False)[ソース]

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)

value"<b>Joel</b> <button>is</button> a <span>slug</span>" であるとき、出力は "Joel is a slug" となります。

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".

django.utils.timezone

utc

tzinfo instance that represents UTC.

class FixedOffset(offset=None, name=None)[ソース]

A tzinfo subclass modeling a fixed offset from UTC. offset is an integer number of minutes east of UTC.

get_fixed_timezone(offset)[ソース]

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()[ソース]

Returns a tzinfo instance that represents the default time zone.

get_default_timezone_name()[ソース]

Returns the name of the default time zone.

get_current_timezone()[ソース]

Returns a tzinfo instance that represents the current time zone.

get_current_timezone_name()[ソース]

Returns the name of the current time zone.

activate(timezone)[ソース]

Sets the current time zone. The timezone argument must be an instance of a tzinfo subclass or a time zone name.

deactivate()[ソース]

Unsets the current time zone.

override(timezone)[ソース]

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=None, timezone=None)[ソース]

Converts an aware datetime to a different time zone, by default the current time zone.

When value is omitted, it defaults to now().

This function doesn’t work on naive datetimes; use make_aware() instead.

Changed in Django 1.11:

In older versions, value is a required argument.

localdate(value=None, timezone=None)[ソース]
New in Django 1.11.

Uses localtime() to convert an aware datetime to a date() in a different time zone, by default the current time zone.

When value is omitted, it defaults to now().

This function doesn’t work on naive datetimes.

now()[ソース]

Returns a datetime that represents the current point in time. Exactly what’s returned depends on the value of USE_TZ:

  • If 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.
  • If 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)[ソース]

Returns True if value is aware, False if it is naive. This function assumes that value is a datetime.

is_naive(value)[ソース]

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)[ソース]

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.

The pytz.AmbiguousTimeError exception is 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.

The pytz.NonExistentTimeError exception is 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.

make_naive(value, timezone=None)[ソース]

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

以下の使い方の完全な説明は、翻訳ドキュメント を参照してください。

gettext(message)[ソース]

message を翻訳し、UTF-8 バイト文字列で返します。

ugettext(message)[ソース]

message を翻訳し、unicode 文字列で返します。

pgettext(context, message)[ソース]

コンテキスト に与えられた message を翻訳し、unicode 文字列で返します。

詳しくは 文脈マーカー を参照してください。

gettext_lazy(message)
ugettext_lazy(message)
pgettext_lazy(context, message)

上述の lazy ではないものと同じですが、遅延処理を使用します。

遅延翻訳ドキュメント を参照してください。

gettext_noop(message)[ソース]
ugettext_noop(message)

翻訳用に文字列をマークしますが、この段階では翻訳しません。(外部で使われる可能性があるため) ベースの言語のままにする必要があるグローバル変数に文字列を保持するために使えます。そして、後の時点で翻訳します。

ngettext(singular, plural, number)[ソース]

singular (単数形) と plural (複数形) を翻訳し、number に基づいた適切な文字列を UTF-8 バイト文字列で返します。

ungettext(singular, plural, number)[ソース]

singular (単数形) と plural (複数形) を翻訳し、number に基づいた適切な文字列を unicode 文字列で返します。

npgettext(context, singular, plural, number)[ソース]

singular (単数形) と plural (複数形) を翻訳し、numbercontext に基づいた適切な文字列を unicode 文字列で返します。

ngettext_lazy(singular, plural, number)[ソース]
ungettext_lazy(singular, plural, number)[ソース]
npgettext_lazy(context, singular, plural, number)[ソース]

上述の lazy ではないものと同じですが、遅延処理を使用します。

遅延翻訳ドキュメント を参照してください。

string_concat(*strings)

バージョン 1.11 で撤廃: Use django.utils.text.format_lazy() instead. string_concat(*strings) can be replaced by format_lazy('{}' * len(strings), *strings).

文字列結合の遅延の形で、複数のパートで構成される翻訳に対して必要となります。

activate(language)[ソース]

渡された language に対して翻訳オブジェクトを取り出し、現在のスレッドに対してカレント翻訳オブジェクトとして有効化します。

deactivate()[ソース]

カレント翻訳オブジェクトを無効化し、さらなる _ 呼び出しが再びデフォルトの翻訳オブジェクトに対して解決するようにします。

deactivate_all()[ソース]

アクティブな翻訳オブジェクトを NullTranslations() のインスタンスにします。何らかの理由で遅延された翻訳を元の文字列で表示したいときに役立ちます。

override(language, deactivate=False)[ソース]

django.utils.translation.activate() を使って、与えられた言語に対して翻訳オブジェクトを取り出す Python コンテキストマネージャです。現在のスレッドに対してこの翻訳オブジェクトを有効化し、退出時に元の言語に戻します。オプションで、 deactivate 引数が True の場合、django.utils.translation.deactivate() を使って退出時に単に一時的な翻訳を無効にするようにできます。language 引数に None を渡した場合、NullTranslations() のインスタンスがコンテキスト内で有効化されます。

override is also usable as a function decorator.

check_for_language(lang_code)[ソース]

与えられた言語コード (例えば 『fr』 や 『pt_BR』) に対するグローバル言語ファイルが存在するかどうかをチェックします。ユーザーが提供する言語が有効かどうかを決めるために使われます。

get_language()[ソース]

現在選択中の言語コードを返します。翻訳が (deactivate_all()Noneoverride() に渡されることによって) 一時的に無効化されている場合は None を返します。

get_language_bidi()[ソース]

選択中の言語の BiDi レイアウトを返します:

  • False = 左から右へのレイアウト
  • True = 右から左へのレイアウト
get_language_from_request(request, check_path=False)[ソース]

リクエストを分析して、ユーザがシステムにどの言語を表示させたいかを明らかにします。settings.LANGUAGES にリストアップされている言語のみが考慮されます。ユーザが主言語の他に副言語をリクエストする場合は、主言語が送信されます。

check_pathTrue の場合、関数はまず、パスが LANGUAGES 設定にリストアップされた言語コードで始まるかどうか、リクエストされた URL をチェックします。

to_locale(language)[ソース]

言語の名前 (en-us) をロケール名 (en_US) に変換します。

templatize(src)[ソース]

Django テンプレートを xgettext によって理解されるものに変更します。Django 翻訳タグを標準的な gettext 関数の文に変換することによって行われます。

LANGUAGE_SESSION_KEY

現在のセッションに対してアクティブな言語が保持されるセッションキーです。