.. TBD

Default: ``None``

If this isn't given or is ``None``, you'll get operating-system

of ``0600``, and files saved from memory will be saved using the

system's standard umask.

**Always prefix the mode with a 0.**

If you're not familiar with file modes, please note that the leading

``0`` is very important: it indicates an octal number, which is the

way that modes must be specified. If you try to use ``644``, you'll

get totally incorrect behavior.

.. TBD

This document describes Django's built-in template tags and filters. It is

recommended that you use the :ref:`automatic documentation

<template-built-in-reference>`, if available, as this will also include

documentation for any custom tags or filters installed.

のようにします。

.. TBD

Note that if the URL you're reversing doesn't exist, you'll get an

:exc:`NoReverseMatch` exception raised, which will cause your site to display an

error page.

**New in development verson:** If you'd like to retrieve a URL without displaying it,

you can use a slightly different call:

This ``{% url ... as var %}`` syntax will *not* cause an error if the view is

missing. In practice you'll use this to link to views that are optional:

.. TBD

The numeric mode (i.e. ``0644``) to set newly uploaded files to. For

more information about what these modes mean, see the `documentation for

os.chmod`_

If this isn't given or is ``None``, you'll get operating-system

dependent behavior. On most platforms, temporary files will have a mode

of ``0600``, and files saved from memory will be saved using the

system's standard umask.

If you're not familiar with file modes, please note that the leading

``0`` is very important: it indicates an octal number, which is the

way that modes must be specified. If you try to use ``644``, you'll

get totally incorrect behavior.

**Always prefix the mode with a ``0``.**

.. TBD

Like regular Python files, you can read the file line-by-line simply by

iterating over the uploaded file:

However, *unlike* standard Python files, :class:`UploadedFile` only

understands ``\n`` (also known as "Unix-style") line endings. If you know

that you need to handle uploaded files with different line endings, you'll

need to do so in your view.

Handling HTTP requests

.. TBD

Information on handling HTTP requests in Django:

.. TBD

Most middleware classes won't need an initializer since middleware classes are

essentially placeholders for the ``process_*`` methods. If you do need some

global state you may use ``__init__`` to set up. However, keep in mind a couple

of caveats:

* Django initializes your middleware without any arguments, so you can't

define ``__init__`` as requiring any arguments.

* Unlike the ``process_*`` methods which get called once per request,

``__init__`` gets called only *once*, when the web server starts up.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

should be used. In these cases, your middleware's ``__init__`` method may raise

``django.core.exceptions.MiddlewareNotUsed``. Django will then remove that piece

.. TBD

Delete the current session data from the database and regenerate the

session key value that is sent back to the user in the cookie. This is

used if you want to ensure that the previous session data can't be

accessed again from the user's browser (for example, the

``django.contrib.auth.logout()`` method calls it).

.. TBD

The standard ``django.contrib.auth.logout()`` function actually does a bit

more than this to prevent inadvertent data leakage. It calls

``request.session.flush()``. We are using this example as a demonstration of

how to work with session objects, not as a full ``logout()`` implementation.

.. TBD

The ``reverse()`` function can reverse a large variety of regular expression

patterns for URLs, but not every possible one. The main restriction at the

moment is that the pattern cannot contain alternative choices using the

vertical bar (``"|"``) character. You can quite happily use such patterns for

matching against incoming URLs and sending them off to views, but you cannot

reverse such patterns.