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pinterest/pymemcache

pymemcache

Master Documentation Status

A comprehensive, fast, pure-Python memcached client.

pymemcache supports the following features:

  • Complete implementation of the memcached text protocol.
  • Connections using UNIX sockets, or TCP over IPv4 or IPv6.
  • Configurable timeouts for socket connect and send/recv calls.
  • Access to the "noreply" flag, which can significantly increase the speed of writes.
  • Flexible, modular and simple approach to serialization and deserialization.
  • The (optional) ability to treat network and memcached errors as cache misses.

Installing pymemcache

Install from pip:

pip install pymemcache

For development, clone from github and run the tests:

git clone https://github.com/pinterest/pymemcache.git
cd pymemcache

Run the tests (make sure you have a local memcached server running):

tox

Usage

See the documentation here: https://pymemcache.readthedocs.io/en/latest/

Django

Since version 3.2, Django has included a pymemcache-based cache backend. See its documentation.

On older Django versions, you can use django-pymemcache.

Comparison with Other Libraries

pylibmc

The pylibmc library is a wrapper around libmemcached, implemented in C. It is fast, implements consistent hashing, the full memcached protocol and timeouts. It does not provide access to the "noreply" flag. It also isn't pure Python, so using it with libraries like gevent is out of the question, and its dependency on libmemcached poses challenges (e.g., it must be built against the same version of libmemcached that it will use at runtime).

python-memcached

The python-memcached library implements the entire memcached text protocol, has a single timeout for all socket calls and has a flexible approach to serialization and deserialization. It is also written entirely in Python, so it works well with libraries like gevent. However, it is tied to using thread locals, doesn't implement "noreply", can't treat errors as cache misses and is slower than both pylibmc and pymemcache. It is also tied to a specific method for handling clusters of memcached servers.

memcache_client

The team at mixpanel put together a pure Python memcached client as well. It has more fine grained support for socket timeouts, only connects to a single host. However, it doesn't support most of the memcached API (just get, set, delete and stats), doesn't support "noreply", has no serialization or deserialization support and can't treat errors as cache misses.

External Links

The memcached text protocol reference page:
https://github.com/memcached/memcached/blob/master/doc/protocol.txt
The python-memcached library (another pure-Python library):
https://github.com/linsomniac/python-memcached
Mixpanel's Blog post about their memcached client for Python:
https://engineering.mixpanel.com/we-went-down-so-we-wrote-a-better-pure-python-memcache-client-b409a9fe07a9
Mixpanel's pure Python memcached client:
https://github.com/mixpanel/memcache_client
Bye-bye python-memcached, hello pymemcache (migration guide)
https://jugmac00.github.io/blog/bye-bye-python-memcached-hello-pymemcache/

Credits

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