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greenlet 0.4.0

Lightweight in-process concurrent programming

Package Documentation

Latest Version: 0.4.13

The greenlet package is a spin-off of Stackless, a version of CPython that supports micro-threads called “tasklets”. Tasklets run pseudo-concurrently (typically in a single or a few OS-level threads) and are synchronized with data exchanges on “channels”.

A “greenlet”, on the other hand, is a still more primitive notion of micro-thread with no implicit scheduling; coroutines, in other words. This is useful when you want to control exactly when your code runs. You can build custom scheduled micro-threads on top of greenlet; however, it seems that greenlets are useful on their own as a way to make advanced control flow structures. For example, we can recreate generators; the difference with Python’s own generators is that our generators can call nested functions and the nested functions can yield values too. Additionally, you don’t need a “yield” keyword. See the example in tests/

Greenlets are provided as a C extension module for the regular unmodified interpreter.

Greenlets are lightweight coroutines for in-process concurrent programming.

Who is using Greenlet?

There are several libraries that use Greenlet as a more flexible alternative to Python’s built in coroutine support:

Getting Greenlet

The easiest way to get Greenlet is to install it with pip or easy_install:

pip install greenlet
easy_install greenlet

Source code archives and windows installers are available on the python package index at

The source code repository is hosted on github:

The master branch - i.e. the development version - can be installed directly by running one of the following:

pip install greenlet==dev
easy_install greenlet==dev
File Type Py Version Uploaded on Size
greenlet-0.4.0-py2.4-win32.egg (md5)
built on Microsoft-Windows
Python Egg 2.4 2012-06-21 11KB
greenlet-0.4.0-py2.5-win32.egg (md5) Python Egg 2.5 2012-06-21 11KB
greenlet-0.4.0-py2.6-win32.egg (md5) Python Egg 2.6 2012-06-21 12KB
greenlet-0.4.0-py2.7-win-amd64.egg (md5) Python Egg 2.7 2012-06-21 13KB
greenlet-0.4.0-py2.7-win32.egg (md5) Python Egg 2.7 2012-06-21 12KB
greenlet-0.4.0-py3.1-win-amd64.egg (md5) Python Egg 3.1 2012-06-21 13KB
greenlet-0.4.0-py3.1-win32.egg (md5) Python Egg 3.1 2012-06-21 12KB
greenlet-0.4.0-py3.2-win-amd64.egg (md5) Python Egg 3.2 2012-06-21 13KB
greenlet-0.4.0-py3.2-win32.egg (md5) Python Egg 3.2 2012-06-21 12KB
greenlet-0.4.0-py3.3-win-amd64.egg (md5) Python Egg 3.3 2012-06-21 13KB
greenlet-0.4.0-py3.3-win32.egg (md5) Python Egg 3.3 2012-06-21 12KB (md5) MS Windows installer 2.7 2012-06-21 235KB (md5) MS Windows installer 3.1 2012-06-21 236KB (md5) MS Windows installer 3.2 2012-06-21 235KB (md5) MS Windows installer 3.3 2012-06-21 233KB
greenlet-0.4.0.win32-py2.4.exe (md5) MS Windows installer 2.4 2012-06-21 74KB
greenlet-0.4.0.win32-py2.5.exe (md5) MS Windows installer 2.5 2012-06-21 74KB
greenlet-0.4.0.win32-py2.6.exe (md5) MS Windows installer 2.6 2012-06-21 207KB
greenlet-0.4.0.win32-py2.7.exe (md5) MS Windows installer 2.7 2012-06-21 207KB
greenlet-0.4.0.win32-py3.1.exe (md5) MS Windows installer 3.1 2012-06-21 207KB
greenlet-0.4.0.win32-py3.2.exe (md5) MS Windows installer 3.2 2012-06-21 207KB
greenlet-0.4.0.win32-py3.3.exe (md5) MS Windows installer 3.3 2012-06-21 202KB (md5) Source 2012-06-21 71KB