Virtualenv

每个应用可能需要各自拥有一套“独立”的Python运行环境。virtualenv就是用来为一个应用创建一套“隔离”的Python运行环境。

pip3 install virtualenv

Create

假定我们要开发一个新的项目，需要一套独立的Python运行环境，可以这么做：

第一步，创建目录：

mkdir myproject
cd myproject/

第二步，创建一个独立的Python运行环境，命名为venv：

virtualenv --no-site-packages venv

Using base prefix '/usr/local/.../Python.framework/Versions/3.4'
New python executable in venv/bin/python3.4
Also creating executable in venv/bin/python
Installing setuptools, pip, wheel...done.

--no-site-packages means no third-party packages would be copied.

Activate

source venv/bin/activate
(venv)Mac:myproject michael$

you can install any packages here with pip, it would be installed in venv environment, won't affects system.

Deactivate

deactivate