MindaugasVaitkus2 / requests-cache

Transparent persistent cache for http://python-requests.org/ library ⛺

Requests-Cache

Summary

requests-cache is a transparent, persistent cache for the python requests library. It can substantially improve performance and reduce network traffic, making it an ideal companion for almost any application using requests.

Complete project documentation can be found at requests-cache.readthedocs.io.

Features

• 🍰 Ease of use: Keep using the requests library you're already familiar with. Add caching with a drop-in replacement for requests.Session, or install globally to add caching to all requests functions.
• 🚀 Performance: Get sub-millisecond response times for cached responses. When they expire, you still save time with conditional requests.
• 💾 Persistence: Works with several storage backends including SQLite, Redis, MongoDB, and DynamoDB; or save responses as plain JSON files, YAML, and more
• ⚙️ Customization: Works out of the box with zero config, but with a robust set of features for configuring and extending the library to suit your needs
• 🕗 Expiration: Keep your cache fresh using Cache-Control, eagerly cache everything for long-term storage, use URL patterns for selective caching, or any combination of strategies
• ✔️ Compatibility: Can be combined with other popular libraries based on requests

Quickstart

First, install with pip:

pip install requests-cache

Then, use requests_cache.CachedSession to make your requests. It behaves like a normal requests.Session, but with caching behavior.

To illustrate, we'll call an endpoint that adds a delay of 1 second, simulating a slow or rate-limited website.

This takes 1 minute:

import requests

session = requests.Session()
for i in range(60):
    session.get('http://httpbin.org/delay/1')

This takes 1 second:

import requests_cache

session = requests_cache.CachedSession('demo_cache')
for i in range(60):
    session.get('http://httpbin.org/delay/1')

With caching, the response will be fetched once, saved to demo_cache.sqlite, and subsequent requests will return the cached response near-instantly.

Patching:

If you don't want to manage a session object, or just want to quickly test it out in your application without modifying any code, requests-cache can also be installed globally, and all requests will be transparently cached:

import requests
import requests_cache

requests_cache.install_cache('demo_cache')
requests.get('http://httpbin.org/delay/1')

Configuration:

A quick example of some of the options available:

from datetime import timedelta
from requests_cache import CachedSession

session = CachedSession(
    'demo_cache',
    use_cache_dir=True                 # Save files in the default user cache dir
    cache_control=True,                # Use Cache-Control headers for expiration, if available
    expire_after=timedelta(days=1),    # Otherwise expire responses after one day
    allowable_methods=['GET', 'POST']  # Cache POST requests to avoid sending the same data twice
    allowable_codes=[200, 400]         # Cache 400 responses as a solemn reminder of your failures
    include_get_headers=True,          # Match all request headers
    ignored_parameters=['api_key'],    # Don't match this param or save it in the cache
    old_data_on_error=True,            # In case of request errors, use stale cache data if possible
)

Next Steps

To find out more about what you can do with requests-cache, see:

• User Guide
• API Reference
• Project Info
• A working example at Real Python: Caching External API Requests
• More examples in the examples/ folder