Requests-Ratelimiter¶
Work in progress
This package is a thin wrapper around pyrate-limiter that adds convenient integration with the requests library.
Features¶
pyrate-limiter
implements the leaky bucket algorithm, supports multiple rate limits, and an optional Redis backendrequests-ratelimiter
can be used as a transport adapter, session, or session mixin for compatibility with otherrequests
-based libraries.Rate limits can be automatically tracked separately per host, and different rate limits can be manually applied to different hosts
Installation¶
pip install requests-ratelimiter
Usage¶
Sessions¶
Example with LimiterSession
:
from pyrate_limiter import Duration, RequestRate
from requests import Session
from requests_ratelimiter import LimiterSession
# Apply a rate-limit (5 requests per second) to all requests
session = LimiterSession(RequestRate(5, Duration.SECOND))
# Make rate-limited requests that stay within 5 requests per second
for _ in range(10):
response = session.get('https://httpbin.org/get')
print(response.json())
Adapters¶
Example with LimiterAdapter
:
from pyrate_limiter import Duration, RequestRate
from requests import Session
from requests_ratelimiter import LimiterAdapter
session = Session()
# Apply a rate-limit (5 requests per second) to all requests
adapter = LimiterAdapter(RequestRate(5, Duration.SECOND))
session.mount('http://', adapter)
session.mount('https://', adapter)
# Make rate-limited requests
for user_id in range(100):
response = session.get(f'https://api.some_site.com/v1/users/{user_id}')
print(response.json())
Per-Host Rate Limits¶
With LimiterAdapter
, you can apply different rate limits to different hosts or URLs:
# Apply different rate limits (2/second and 100/minute) to a specific host
adapter_2 = LimiterAdapter(
RequestRate(2, Duration.SECOND),
RequestRate(100, Duration.MINUTE),
)
session.mount('https://api.some_site.com', adapter_2)
Behavior for matching requests is the same as other transport adapters: requests
will use the
adapter with the most specific (i.e., longest) URL prefix for a given request. For example:
session.mount('https://api.some_site.com/v1', adapter_3)
session.mount('https://api.some_site.com/v1/users', adapter_4)
# This request will use adapter_3
session.get('https://api.some_site.com/v1/')
# This request will use adapter_4
session.get('https://api.some_site.com/v1/users/1234')
Per-Host Rate Limit Tracking¶
With either LimiterSession
or LimiterAdapter
, you can automatically track rate limits separately
for each host; in other words, requests sent to one host will not count against the rate limit for
any other hosts. This can be enabled with the per_host
option:
session = LimiterSession(RequestRate(5, Duration.SECOND), per_host=True)
# Make requests for two different hosts
for _ in range(10):
response = session.get(f'https://httpbin.org/get')
print(response.json())
session.get(f'https://httpbingo.org/get')
print(response.json())
Compatibility¶
There are many other useful libraries out there that add features to requests
, most commonly by
extending or modifying
requests.Session.
To use requests-ratelimiter
with one of these libraries, you have at least two options:
Mount a
LimiterAdapter
on an instance of the library’sSession
classUse
LimiterMixin
to create a customSession
class with features from both libraries
Requests-Cache¶
For example, to combine with requests-cache, which also includes a separate mixin class:
from requests_cache import CacheMixin
from requests_ratelimiter import LimiterMixin
class CachedLimiterSession(LimiterMixin, CacheMixin, Session):
"""Session class with caching and rate-limiting behavior. Accepts arguments for both
LimiterSession and CachedSession.
"""
session = CachedLimiterSession(RequestRate(5, Duration.SECOND), backend='redis')
This example has an extra benefit: cache hits won’t count against your rate limit!