mirror of
https://github.com/django/django.git
synced 2025-10-26 07:06:08 +00:00
74f386dba2
git-svn-id: http://code.djangoproject.com/svn/django/trunk@8987 bcc190cf-cafb-0310-a4f2-bffc1f526a37
122 lines
3.6 KiB
Plaintext
122 lines
3.6 KiB
Plaintext
.. _ref-files-file:
|
|
|
|
The ``File`` object
|
|
===================
|
|
|
|
.. currentmodule:: django.core.files
|
|
|
|
.. class:: File(file_object)
|
|
|
|
``File`` attributes and methods
|
|
-------------------------------
|
|
|
|
Django's ``File`` has the following attributes and methods:
|
|
|
|
.. attribute:: File.name
|
|
|
|
The name of file including the relative path from :setting:`MEDIA_ROOT`.
|
|
|
|
.. attribute:: File.path
|
|
|
|
The absolute path to the file's location on a local filesystem.
|
|
|
|
:ref:`Custom file storage systems <howto-custom-file-storage>` may not store
|
|
files locally; files stored on these systems will have a ``path`` of
|
|
``None``.
|
|
|
|
.. attribute:: File.url
|
|
|
|
The URL where the file can be retrieved. This is often useful in
|
|
:ref:`templates <topics-templates>`; for example, a bit of a template for
|
|
displaying a ``Car`` (see above) might look like:
|
|
|
|
.. code-block:: html+django
|
|
|
|
<img src='{{ car.photo.url }}' alt='{{ car.name }}' />
|
|
|
|
.. attribute:: File.size
|
|
|
|
The size of the file in bytes.
|
|
|
|
.. method:: File.open(mode=None)
|
|
|
|
Open or reopen the file (which by definition also does ``File.seek(0)``).
|
|
The ``mode`` argument allows the same values as Python's standard
|
|
``open()``.
|
|
|
|
When reopening a file, ``mode`` will override whatever mode the file was
|
|
originally opened with; ``None`` means to reopen with the original mode.
|
|
|
|
.. method:: File.read(num_bytes=None)
|
|
|
|
Read content from the file. The optional ``size`` is the number of bytes to
|
|
read; if not specified, the file will be read to the end.
|
|
|
|
.. method:: File.__iter__()
|
|
|
|
Iterate over the file yielding one line at a time.
|
|
|
|
.. method:: File.chunks(chunk_size=None)
|
|
|
|
Iterate over the file yielding "chunks" of a given size. ``chunk_size``
|
|
defaults to 64 KB.
|
|
|
|
This is especially useful with very large files since it allows them to be
|
|
streamed off disk and avoids storing the whole file in memory.
|
|
|
|
.. method:: File.multiple_chunks(chunk_size=None)
|
|
|
|
Returns ``True`` if the file is large enough to require multiple chunks to
|
|
access all of its content give some ``chunk_size``.
|
|
|
|
.. method:: File.write(content)
|
|
|
|
Writes the specified content string to the file. Depending on the storage
|
|
system behind the scenes, this content might not be fully committed until
|
|
``close()`` is called on the file.
|
|
|
|
.. method:: File.close()
|
|
|
|
Close the file.
|
|
|
|
Additional ``ImageField`` attributes
|
|
------------------------------------
|
|
|
|
.. attribute:: File.width
|
|
|
|
Width of the image.
|
|
|
|
.. attribute:: File.height
|
|
|
|
Height of the image.
|
|
|
|
Additional methods on files attached to objects
|
|
-----------------------------------------------
|
|
|
|
.. highlight:: pycon
|
|
|
|
Any :class:`File` that's associated with an object (as with ``Car.photo``,
|
|
above) will also have a couple of extra methods:
|
|
|
|
.. method:: File.save(name, content, save=True)
|
|
|
|
Saves a new file with the file name and contents provided. This will not
|
|
replace the existing file, but will create a new file and update the object
|
|
to point to it. If ``save`` is ``True``, the model's ``save()`` method will
|
|
be called once the file is saved. That is, these two lines::
|
|
|
|
>>> car.photo.save('myphoto.jpg', contents, save=False)
|
|
>>> car.save()
|
|
|
|
are the same as this one line::
|
|
|
|
>>> car.photo.save('myphoto.jpg', contents, save=True)
|
|
|
|
Note that the ``content`` argument must be an instance of
|
|
:class:`File` or of a subclass of :class:`File`.
|
|
|
|
.. method:: File.delete(save=True)
|
|
|
|
Remove the file from the model instance and delete the underlying file. The
|
|
``save`` argument works as above.
|