[Mac][Python][Virtualenv]安装配置和使用

安装帮助文档安装VirtualEnv报错如下

tekiMacBook-Air:workspaces hbai$ source /usr/local/bin/virtualenvwrapper.sh
/usr/bin/python: No module named virtualenvwrapper
virtualenvwrapper.sh: There was a problem running the initialization hooks. 

If Python could not import the module virtualenvwrapper.hook_loader,
check that virtualenvwrapper has been installed for
VIRTUALENVWRAPPER_PYTHON=/usr/bin/python and that PATH is
set properly.
tekiMacBook-Air:workspaces hbai$ which python
/usr/bin/python

检查后发现因为Mac本机自带的python2.7 安装在/usr/bin 下面，但是安装了pycharm后会在/usr/local/bin会有python3.0的执行文件，所以本地的调用基本都被pycharm接管了。

因此给py2.7安装相对应的环境时候，需要通过pycharm来进行安装virtalenv 和 virtualenvwrapper才可以

安装完毕后再在命令行执行即可

直接创建虚拟环境 $ virtualenv env1
导入环境变量以后通过mkvirtualenv 创建虚拟环境
- 　　$export WORKON_HOME=~/workspaces
- 　　$source /usr/local/bin/virtualenvwrapper.sh
- 　　$mkvirtualenv env1

通过这种方式创建的python环境就是3.4的了

testtekiMacBook-Air:workspaces test$ virtualenv env1
Using base prefix '/Library/Frameworks/Python.framework/Versions/3.4'
New python executable in /Users/test/workspaces/env1/bin/python3.4
Also creating executable in /Users/test/workspaces/env1/bin/python
Installing setuptools, pip, wheel...done.
testtekiMacBook-Air:workspaces test$ ls
env1
testtekiMacBook-Air:workspaces test$ rm -rf env1/
testtekiMacBook-Air:workspaces test$ export WORKON_HOME=~/workspaces
testtekiMacBook-Air:workspaces test$ source /usr/local/bin/virtualenvwrapper.sh
virtualenvwrapper.user_scripts creating /Users/test/workspaces/initialize
virtualenvwrapper.user_scripts creating /Users/test/workspaces/premkvirtualenv
virtualenvwrapper.user_scripts creating /Users/test/workspaces/postmkvirtualenv
virtualenvwrapper.user_scripts creating /Users/test/workspaces/prermvirtualenv
virtualenvwrapper.user_scripts creating /Users/test/workspaces/postrmvirtualenv
virtualenvwrapper.user_scripts creating /Users/test/workspaces/predeactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/postdeactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/preactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/postactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/get_env_details
virtualenvwrapper.user_scripts creating /Users/test/workspaces/premkproject
virtualenvwrapper.user_scripts creating /Users/test/workspaces/postmkproject
testtekiMacBook-Air:workspaces test$ ls
get_env_details        postactivate        postmkproject        postrmvirtualenv    predeactivate        premkvirtualenv
initialize        postdeactivate        postmkvirtualenv    preactivate        premkproject        prermvirtualenv
testtekiMacBook-Air:workspaces test$ mkvirtualenv env1
Using base prefix '/Library/Frameworks/Python.framework/Versions/3.4'
New python executable in /Users/test/workspaces/env1/bin/python3.4
Also creating executable in /Users/test/workspaces/env1/bin/python
Installing setuptools, pip, wheel...done.
virtualenvwrapper.user_scripts creating /Users/test/workspaces/env1/bin/predeactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/env1/bin/postdeactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/env1/bin/preactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/env1/bin/postactivate
virtualenvwrapper.user_scripts creating /Users/test/workspaces/env1/bin/get_env_details
(env1) testtekiMacBook-Air:workspaces test$ python
Python 3.4.0 (v3.4.0:04f714765c13, Mar 15 2014, 23:02:41) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>

注：如果需要使用mac原先自带的py2.7的环境进行创建virtual env,步骤如下：

需要指定pip3的安装以及设置VIRTUALENVWRAPPER的工作路径，但是不推荐，因为这样运行环境是py2.7的

$ /usr/local/bin/pip3 install virtualenv virtualenvwrapper
$ export VIRTUALENVWRAPPER_PYTHON=/usr/local/bin/python3
$ source /usr/local/bin/virtualenvwrapper.sh

常用命令：

列出虚拟环境：
```
$ lsvirtualenv -b
env1
env2
```
切换虚拟环境：
```
$ workon env1
```
查看环境里安装了哪些包：
```
$ lssitepackages
```
进入当前环境：
```
$ cdvirtualenv
```
进入当前环境的site-packages：
```
$ cdsitepackages
$ cdsitepackages pip
```

复制虚拟环境：

$ cpvirtualenv env1 env3
Copying env1 as env3...

退出虚拟环境：
```
$ deactivate
```
删除虚拟环境：
```
$ rmvirtualenv env2
Removing env2...
```

参考文档： http://www.jianshu.com/p/51140800e8b4#

http://stackoverflow.com/questions/29486113/problems-with-python-and-virtualenvwrapper-after-updating-no-module-named-virtu

http://stackoverflow.com/questions/27308234/usr-bin-python-vs-opt-local-bin-python2-7-on-os-x