# Documentazione Django 6.0.7

# File storage API

## Getting the default storage class

Django provides convenient ways to access the default storage class:

storages

  A dictionary-like object that allows retrieving a storage instance using its alias as defined by `STORAGES`.

  `storages` has an attribute `backends`, which defaults to the raw value provided in `STORAGES`.

  Additionally, `storages` provides a `create_storage()` method that accepts the dictionary used in `STORAGES` for a backend, and returns a storage instance based on that backend definition. This may be useful for third-party packages needing to instantiate storages in tests:

      >>> from django.core.files.storage import storages
      >>> storages.backends
      {'default': {'BACKEND': 'django.core.files.storage.FileSystemStorage'},
       'staticfiles': {'BACKEND': 'django.contrib.staticfiles.storage.StaticFilesStorage'},
       'custom': {'BACKEND': 'package.storage.CustomStorage'}}
      >>> storage_instance = storages.create_storage({"BACKEND": "package.storage.CustomStorage"})

class DefaultStorage

  `DefaultStorage` provides lazy access to the default storage system as defined by `default` key in `STORAGES`. `DefaultStorage` uses `storages` internally.

default_storage

  `default_storage` is an instance of the `DefaultStorage`.

## The `FileSystemStorage` class

class FileSystemStorage(location=None, base_url=None, file_permissions_mode=None, directory_permissions_mode=None, allow_overwrite=False)

  The `FileSystemStorage` class implements basic file storage on a local filesystem. It inherits from `Storage` and provides implementations for all the public methods thereof.

  Nota

  The `FileSystemStorage.delete()` method will not raise an exception if the given file name does not exist.

  location

    Absolute path to the directory that will hold the files. Defaults to the value of your `MEDIA_ROOT` setting.

  base_url

    URL that serves the files stored at this location. Defaults to the value of your `MEDIA_URL` setting.

  file_permissions_mode

    The file system permissions that the file will receive when it is saved. Defaults to `FILE_UPLOAD_PERMISSIONS`.

  directory_permissions_mode

    The file system permissions that the directory will receive when it is saved. Defaults to `FILE_UPLOAD_DIRECTORY_PERMISSIONS`.

  allow_overwrite

    Flag to control allowing saving a new file over an existing one. Defaults to `False`.

  get_created_time(name)

    Returns a `datetime` of the system’s ctime, i.e. `os.path.getctime()`. On some systems (like Unix), this is the time of the last metadata change, and on others (like Windows), it’s the creation time of the file.

## The `InMemoryStorage` class

class InMemoryStorage(location=None, base_url=None, file_permissions_mode=None, directory_permissions_mode=None)

  The `InMemoryStorage` class implements a memory-based file storage. It has no persistence, but can be useful for speeding up tests by avoiding disk access.

  location

    Absolute path to the directory name assigned to files. Defaults to the value of your `MEDIA_ROOT` setting.

  base_url

    URL that serves the files stored at this location. Defaults to the value of your `MEDIA_URL` setting.

  file_permissions_mode

    The file system permissions assigned to files, provided for compatibility with `FileSystemStorage`. Defaults to `FILE_UPLOAD_PERMISSIONS`.

  directory_permissions_mode

    The file system permissions assigned to directories, provided for compatibility with `FileSystemStorage`. Defaults to `FILE_UPLOAD_DIRECTORY_PERMISSIONS`.

## The `Storage` class

class Storage

  The `Storage` class provides a standardized API for storing files, along with a set of default behaviors that all other storage systems can inherit or override as necessary.

  Nota

  When methods return naive `datetime` objects, the effective timezone used will be the current value of `os.environ['TZ']`; note that this is usually set from Django’s `TIME_ZONE`.

  delete(name)

    Deletes the file referenced by `name`. If deletion is not supported on the target storage system this will raise `NotImplementedError` instead.

  exists(name)

    Returns `True` if a file referenced by the given name already exists in the storage system.

  get_accessed_time(name)

    Returns a `datetime` of the last accessed time of the file. For storage systems unable to return the last accessed time this will raise `NotImplementedError`.

    If `USE_TZ` is `True`, returns an aware `datetime`, otherwise returns a naive `datetime` in the local timezone.

  get_alternative_name(file_root, file_ext)

    Returns an alternative filename based on the `file_root` and `file_ext` parameters, an underscore plus a random 7 character alphanumeric string is appended to the filename before the extension.

  get_available_name(name, max_length=None)

    Returns a filename based on the `name` parameter that’s free and available for new content to be written to on the target storage system.

    The length of the filename will not exceed `max_length`, if provided. If a free unique filename cannot be found, a `SuspiciousFileOperation` exception will be raised.

    If a file with `name` already exists, `get_alternative_name()` is called to obtain an alternative name.

  get_created_time(name)

    Returns a `datetime` of the creation time of the file. For storage systems unable to return the creation time this will raise `NotImplementedError`.

    If `USE_TZ` is `True`, returns an aware `datetime`, otherwise returns a naive `datetime` in the local timezone.

  get_modified_time(name)

    Returns a `datetime` of the last modified time of the file. For storage systems unable to return the last modified time this will raise `NotImplementedError`.

    If `USE_TZ` is `True`, returns an aware `datetime`, otherwise returns a naive `datetime` in the local timezone.

  get_valid_name(name)

    Returns a filename based on the `name` parameter that’s suitable for use on the target storage system.

  generate_filename(filename)

    Validates the `filename` by calling `get_valid_name` and returns a filename to be passed to the `save()` method.

    The `filename` argument may include a path as returned by `FileField.upload_to`. In that case, the path won’t be passed to `get_valid_name` but will be prepended back to the resulting name.

    The default implementation uses `os.path` operations. Override this method if that’s not appropriate for your storage.

  listdir(path)

    Lists the contents of the specified path, returning a 2-tuple of lists; the first item being directories, the second item being files. For storage systems that aren’t able to provide such a listing, this will raise a `NotImplementedError` instead.

  open(name, mode='rb')

    Opens the file given by `name`. Note that although the returned file is guaranteed to be a `File` object, it might actually be some subclass. In the case of remote file storage this means that reading/writing could be quite slow, so be warned.

  path(name)

    The local filesystem path where the file can be opened using Python’s standard `open()`. For storage systems that aren’t accessible from the local filesystem, this will raise `NotImplementedError` instead.

  save(name, content, max_length=None)

    Saves a new file using the storage system, preferably with the name specified. If there already exists a file with this name `name`, the storage system may modify the filename as necessary to get a unique name. The actual name of the stored file will be returned.

    The `max_length` argument is passed along to `get_available_name()`.

    The `content` argument must be an instance of `django.core.files.File` or a file-like object that can be wrapped in `File`.

  size(name)

    Returns the total size, in bytes, of the file referenced by `name`. For storage systems that aren’t able to return the file size this will raise `NotImplementedError` instead.

  url(name)

    Returns the URL where the contents of the file referenced by `name` can be accessed. For storage systems that don’t support access by URL this will raise `NotImplementedError` instead.

There are community-maintained solutions too!

Django has a vibrant ecosystem. There are storage backends highlighted on the Community Ecosystem page. The Django Packages Storage Backends grid has even more options for you!