File
object¶The django.core.files
module and its submodules contain built-in classes
for basic file handling in Django.
File
class¶The File
class is a thin wrapper around a Python
file object with some Django-specific additions.
Internally, Django uses this class when it needs to represent a file.
File
objects have the following attributes and methods:
The name of the file including the relative path from
MEDIA_ROOT
.
The size of the file in bytes.
The underlying file object that this class wraps.
Be careful with this attribute in subclasses.
Some subclasses of File
, including
ContentFile
and
FieldFile
, may replace this
attribute with an object other than a Python file object.
In these cases, this attribute may itself be a File
subclass (and not necessarily the same subclass). Whenever
possible, use the attributes and methods of the subclass itself
rather than the those of the subclass’s file
attribute.
The read/write mode for the file.
Open or reopen the file (which also does File.seek(0)
).
The mode
argument allows the same values
as Python’s built-in open()
.
When reopening a file, mode
will override whatever mode the file
was originally opened with; None
means to reopen with the original
mode.
It can be used as a context manager, e.g. with file.open() as f:
.
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.
Returns True
if the file is large enough to require multiple chunks
to access all of its content give some chunk_size
.
In addition to the listed methods, File
exposes
the following attributes and methods of its file
object:
encoding
, fileno
, flush
, isatty
, newlines
, read
,
readinto
, readline
, readlines
, seek
, tell
,
truncate
, write
, writelines
, readable()
, writable()
,
and seekable()
.
ContentFile
class¶The ContentFile
class inherits from File
,
but unlike File
it operates on string content
(bytes also supported), rather than an actual file. For example:
from django.core.files.base import ContentFile
f1 = ContentFile("esta frase está en español")
f2 = ContentFile(b"these are bytes")
ImageFile
class¶Django provides a built-in class specifically for images.
django.core.files.images.ImageFile
inherits all the attributes
and methods of File
, and additionally
provides the following:
Width of the image in pixels.
Height of the image in pixels.
Any File
that is associated with an object (as with Car.photo
,
below) will also have a couple of extra methods:
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', content, save=False)
>>> car.save()
are equivalent to:
>>> car.photo.save('myphoto.jpg', content, save=True)
Note that the content
argument must be an instance of either
File
or of a subclass of File
, such as
ContentFile
.
Removes the file from the model instance and deletes the underlying file.
If save
is True
, the model’s save()
method will be called once
the file is deleted.
Dec 25, 2023