File storage API

Getting the current storage class

Django provides two convenient ways to access the current storage class:

When called without the import_path parameter get_storage_classwill return the current default storage system as defined byDEFAULT_FILE_STORAGE. If import_path is provided,get_storage_class will attempt to import the class or module from thegiven path and will return it if successful. An exception will beraised if the import is unsuccessful.

The FileSystemStorage class

  • class FileSystemStorage(location=None, base_url=None, file_permissions_mode=None, directory_permissions_mode=None)

  • The FileSystemStorage class implementsbasic file storage on a local filesystem. It inherits fromStorage and provides implementationsfor all the public methods thereof.

    • 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 issaved. Defaults to FILE_UPLOAD_PERMISSIONS.

    • directory_permissions_mode

    • The file system permissions that the directory will receive when it issaved. Defaults to FILE_UPLOAD_DIRECTORY_PERMISSIONS.

Note

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

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

The Storage class

  • class Storage
  • The Storage class provides astandardized API for storing files, along with a set of defaultbehaviors that all other storage systems can inherit or overrideas necessary.

Note

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

  • delete(name)

  • Deletes the file referenced by name. If deletion is not supportedon the target storage system this will raise NotImplementedErrorinstead

  • exists(name)

  • Returns True if a file referenced by the given name already existsin the storage system, or False if the name is available for a newfile.

  • getaccessed_time(_name)

  • Returns a datetime of the last accessed time of thefile. For storage systems unable to return the last accessed time thiswill raise NotImplementedError.

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

  • getalternative_name(_file_root, file_ext)
  • New in Django 3.0:

Returns an alternative filename based on the file_root andfile_ext parameters, an underscore plus a random 7 characteralphanumeric string is appended to the filename before the extension.

  • getavailable_name(_name, max_length=None)
  • Returns a filename based on the name parameter that’s free andavailable for new content to be written to on the target storagesystem.

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

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

  • getcreated_time(_name)
  • Returns a datetime of the creation time of the file.For storage systems unable to return the creation time this will raiseNotImplementedError.

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

  • getmodified_time(_name)
  • Returns a datetime of the last modified time of thefile. For storage systems unable to return the last modified time thiswill raise NotImplementedError.

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

  • getvalid_name(_name)

  • Returns a filename based on the name parameter that’s suitablefor use on the target storage system.

  • generatefilename(_filename)

  • Validates the filename by calling get_valid_name() andreturns a filename to be passed to the save() method.

The filename argument may include a path as returned byFileField.upload_to.In that case, the path won’t be passed to get_valid_name() butwill be prepended back to the resulting name.

The default implementation uses os.path operations. Overridethis 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. Forstorage systems that aren’t able to provide such a listing, this willraise a NotImplementedError instead.

  • open(name, mode='rb')

  • Opens the file given by name. Note that although the returned fileis guaranteed to be a File object, it might actually be somesubclass. In the case of remote file storage this means thatreading/writing could be quite slow, so be warned.

  • path(name)

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

  • save(name, content, max_length=None)

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

The max_length argument is passed along toget_available_name().

The content argument must be an instance ofdjango.core.files.File or a file-like object that can bewrapped 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 willraise NotImplementedError instead.

  • url(name)

  • Returns the URL where the contents of the file referenced by namecan be accessed. For storage systems that don’t support access by URLthis will raise NotImplementedError instead.