This backend stores responses in files on the local filesystem, with one file per response.

Use Cases#

This backend is useful if you would like to use your cached response data outside of requests-cache, for example:

  • Manually viewing cached responses without the need for extra tools (e.g., with a simple text editor)

  • Using cached responses as sample data for automated tests

  • Reading cached responses directly from another application or library, without depending on requests-cache

Usage Example#

Initialize with a FileCache instance:

>>> from requests_cache import CachedSession, FileCache
>>> session = CachedSession(backend=FileCache())

Or by alias:

>>> session = CachedSession(backend='filesystem')

File Formats#

By default, responses are saved as JSON files. If you prefer a different format, you can use of the other available Serializers or provide your own. For example, to save responses as YAML files (requires pyyaml):

>>> session = CachedSession('~/http_cache', backend='filesystem', serializer='yaml')
>>> session.get('')

Cache Files#

  • See Cache Files for general info on specifying cache paths

  • The path for a given response will be in the format <cache_name>/<cache_key>

  • Redirects are stored in a separate SQLite database, located at <cache_name>/redirects.sqlite

  • Use FileCache.paths() to get a list of all cached response paths:

>>> print(list(session.cache.paths()))
> ['/home/user/http_cache/4dc151d95200ec.yaml']

Performance and Limitations#

  • Write performance will vary based on the serializer used, in the range of roughly 1-3ms per write.

  • This backend stores response files in a single directory, and does not currently implement fan-out. This means that on most filesystems, storing a very large number of responses will result in reduced performance.

  • This backend currently uses a simple threading lock rather than a file lock system, so it is not an ideal choice for highly parallel applications.