RateLimiter
===========

|Build Status|

Simple Python module providing rate limiting.

Overview
--------

This package provides the ``ratelimiter`` module, which ensures that an
operation will not be executed more than a given number of times on a
given period. This can prove useful when working with third parties APIs
which require for example a maximum of 10 requests per second.

Usage
-----

Decorator flavor:

::

    >>> from ratelimiter import RateLimiter
    >>> @RateLimiter(max_calls=10, period=1.0)
    ... def do_something():
    ...     pass
    ...

Context manager flavor:

::

    >>> from ratelimiter import RateLimiter
    >>> rate_limiter = RateLimiter(max_calls=10, period=1.0)
    >>> for i in range(100):
    ...     with rate_limiter:
    ...         do_something()
    ...

Using with callback:

::

    >>> from ratelimiter import RateLimiter
    >>> import time
    >>> def limited(until):
    ...     duration = int(round(until - time.time()))
    ...     print('Rate limited, sleeping for %d seconds' % duration)
    ...
    >>> rate_limiter = RateLimiter(max_calls=2, period=3, callback=limited)
    >>> for i in range(3):
    ...     with rate_limiter:
    ...         print('Iteration', i)
    ...
    Iteration 0
    Iteration 1
    Rate limited, sleeping for 3 seconds
    Iteration 2

License
-------

| Original work Copyright 2013 Arnaud Porterie
| Modified work Copyright 2015 Frazer McLean

Licensed under the Apache License, Version 2.0 (the "License"); you may
not use this file except in compliance with the License. You may obtain
a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

.. |Build Status| image:: https://travis-ci.org/RazerM/ratelimiter.png
   :target: https://travis-ci.org/RazerM/ratelimiter
