virtualenv 用于 Python 的版本管理和环境隔离。

practice on MacOS

安装

$ pip install virtualenv virtualenvwrapper
Collecting virtualenv
  Downloading https://files.pythonhosted.org/packages/b6/30/96a02b2287098b23b875bc8c2f58071c35d2efe84f747b64d523721dc2b5/virtualenv-16.0.0-py2.py3-none-any.whl (1.9MB)
    100% |████████████████████████████████| 1.9MB 3.4MB/s
Collecting virtualenvwrapper
  Downloading https://files.pythonhosted.org/packages/2b/8c/3192e10913ad945c0f0fcb17e9b2679434a28ad58ee31ce0104cba3b1154/virtualenvwrapper-4.8.2-py2.py3-none-any.whl
  ....
  ....

  Requirement already satisfied: six>=1.10.0 in /usr/local/lib/python2.7/site-packages (from stevedore->virtualenvwrapper) (1.11.0)
Installing collected packages: virtualenv, pbr, stevedore, virtualenv-clone, virtualenvwrapper
Successfully installed pbr-5.1.0 stevedore-1.30.0 virtualenv-16.0.0 virtualenv-clone-0.4.0 virtualenvwrapper-4.8.2

使用

$ virtualenv [-p <PYTHON_INTERPRETER_PATH>] venv # 创建环境，venv是目录名，自定义

$ source venv/bin/activate # 激活虚拟环境

$ virtualenv -p /usr/local/bin/python3 venv
Running virtualenv with interpreter /usr/local/bin/python3
Using base prefix '/usr/local/Cellar/python/3.6.5/Frameworks/Python.framework/Versions/3.6'
New python executable in /Users/royzeng/venv/bin/python3.6
Also creating executable in /Users/royzeng/venv/bin/python
Installing setuptools, pip, wheel...done.

激活使用

$ cd venv
$ source bin/activate
(venv)
$ which python
/Users/royzeng/venv/bin/python
(venv)
$ python --version
Python 3.6.5
(venv)
$ pip --version
pip 18.1 from /Users/royzeng/venv/lib/python3.6/site-packages/pip (python 3.6)
(venv)

默认的python2 已经变成了python3.

virtualenvwrapper 用法

virtualenvwrapper 是用来管理 virtualenv 的。当你有多个虚拟环境，用它就比较方便了

配置：

# ~/.zshrc
export WORKON_HOME=$HOME/.virtualenvs
source /usr/local/bin/virtualenvwrapper.sh

使用：

• 创建虚拟环境 $ mkvirtualenv [-p <PYTHON_PATH>] <VENV_NAME>
• 查看现有的环境： $ workon
• 切换到指定的环境： $ workon <VENV_NAME>

要删除环境的话，到 ~/.virtualenvs/ 里删除相应的目录就行了。

e.g.

配置文件生效

$ source ~/.zshrc
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/premkproject
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/postmkproject
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/initialize
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/premkvirtualenv
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/postmkvirtualenv
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/prermvirtualenv
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/postrmvirtualenv
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/predeactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/postdeactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/preactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/postactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/get_env_details

创建虚拟环境

$ mkvirtualenv -p /usr/local/bin/python3 myp3
Running virtualenv with interpreter /usr/local/bin/python3
Using base prefix '/usr/local/Cellar/python/3.6.5/Frameworks/Python.framework/Versions/3.6'
New python executable in /Users/royzeng/.virtualenvs/myp3/bin/python3.6
Also creating executable in /Users/royzeng/.virtualenvs/myp3/bin/python
Installing setuptools, pip, wheel...done.
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp3/bin/predeactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp3/bin/postdeactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp3/bin/preactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp3/bin/postactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp3/bin/get_env_details
(myp3)
$ mkvirtualenv -p /usr/local/bin/python myp2
Running virtualenv with interpreter /usr/local/bin/python
New python executable in /Users/royzeng/.virtualenvs/myp2/bin/python2.7
Also creating executable in /Users/royzeng/.virtualenvs/myp2/bin/python
Installing setuptools, pip, wheel...done.
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp2/bin/predeactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp2/bin/postdeactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp2/bin/preactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp2/bin/postactivate
virtualenvwrapper.user_scripts creating /Users/royzeng/.virtualenvs/myp2/bin/get_env_details
(myp2)

查看当前虚拟环境目录

$ workon
myp2
myp3
(myp3)
$ which python
/Users/royzeng/.virtualenvs/myp3/bin/python
(myp3)

切换虚拟环境

$ workon myp2
(myp2)

退出虚拟环境

$ deactivate

删除虚拟环境

$ rmvirtualenv myp2
Removing myp2...
(myp3)