gevent is a coroutine -based Python networking library that uses greenlet to provide a high-level synchronous API on top of the libev or libuv event loop.
Features include:
Fast event loop based on libev or libuv.
Lightweight execution units based on greenlets.
API that re-uses concepts from the Python standard library (for examples there are events and queues).
Cooperative sockets with SSL support
Cooperative DNS queries performed through a threadpool, dnspython, or c-ares.
Monkey patching utility to get 3rd party modules to become cooperative
TCP/UDP/HTTP servers
Subprocess support (through gevent.subprocess)
Thread pools