aiohttp-client-cache 0.5.0

Persistent cache for aiohttp requests

aiohttp-client-cache

aiohttp-client-cache is an async persistent cache for aiohttp client requests, based on requests-cache.

Features

• Ease of use: Use as a drop-in replacement for aiohttp.ClientSession
• Customization: Works out of the box with little to no config, but with plenty of options available for customizing cache expiration and other behavior
• Persistence: Includes several storage backends: SQLite, DynamoDB, MongoDB, and Redis.

Development Status

This library is a work in progress!

Breaking changes should be expected until a 1.0 release, so version pinning is recommended.

My goal for this library is to eventually have a similar (but not identical) feature set as requests-cache, and also contribute new features from this library back to requests-cache. If there is a feature you want, if you've discovered a bug, or if you have other general feedback, please create an issue for it!

Quickstart

First, install with pip (python 3.7+ required):

pip install aiohttp-client-cache

Basic Usage

Next, use aiohttp_client_cache.CachedSession in place of aiohttp.ClientSession. To briefly demonstrate how to use it:

Replace this:

from aiohttp import ClientSession

async with ClientSession() as session:
    await session.get('http://httpbin.org/delay/1')

With this:

from aiohttp_client_cache import CachedSession, SQLiteBackend

async with CachedSession(cache=SQLiteBackend('demo_cache')) as session:
    await session.get('http://httpbin.org/delay/1')

The URL in this example adds a delay of 1 second, simulating a slow or rate-limited website. With caching, the response will be fetched once, saved to demo_cache.sqlite, and subsequent requests will return the cached response near-instantly.

Configuration

Several options are available to customize caching behavior. This example demonstrates a few of them:

# fmt: off
from aiohttp_client_cache import SQLiteBackend

cache = SQLiteBackend(
    cache_name='~/.cache/aiohttp-requests.db',  # For SQLite, this will be used as the filename
    expire_after=60*60,                         # By default, cached responses expire in an hour
    urls_expire_after={'*.fillmurray.com': -1}, # Requests for any subdomain on this site will never expire
    allowed_codes=(200, 418),                   # Cache responses with these status codes
    allowed_methods=['GET', 'POST'],            # Cache requests with these HTTP methods
    include_headers=True,                       # Cache requests with different headers separately
    ignored_params=['auth_token'],              # Keep using the cached response even if this param changes
    timeout=2.5,                                # Connection timeout for SQLite backend
)

More Info

To learn more, see:

• User Guide
• Cache Backends
• API Reference
• Examples