windows下的virtualenv使用

virtualenv的优点
1.使不同的应用开发环境独立
2.环境升级不影响其他应用，也不影响全局的python环境
3.它可以防止系统中出现包管理混乱和版本的冲突

#安装virtualenv
C:\Users\Administrator>pip install virtualenv
Requirement already satisfied: virtualenv in d:\python\lib\site-packages
#cd到一个目录中
C:\Users\Administrator>cd C:\Users\Administrator\Desktop
#在这个目录中建立文件夹testdir
C:\Users\Administrator\Desktop>virtualenv testdir
Using base prefix 'd:\\python'
New python executable in C:\Users\Administrator\Desktop\testdir\Scripts\python.e
xe
Installing setuptools, pip, wheel...done.
#cd到testdir/Scripts文件夹下
C:\Users\Administrator\Desktop>cd testdir
C:\Users\Administrator\Desktop\testdir>cd Scripts
#激活虚拟环境
C:\Users\Administrator\Desktop\testdir\Scripts>activate.bat
#退出虚拟环境
(testdir) C:\Users\Administrator\Desktop\testdir\Scripts>deactivate.bat

#安装virtualwrapper-win
C:\Users\Administrator\Desktop\testdir\Scripts>pip install virtualenvwrapper-win
Collecting virtualenvwrapper-win
  Downloading virtualenvwrapper-win-1.2.2.tar.gz
Collecting virtualenv (from virtualenvwrapper-win)
  Using cached virtualenv-15.1.0-py2.py3-none-any.whl
Building wheels for collected packages: virtualenvwrapper-win
  Running setup.py bdist_wheel for virtualenvwrapper-win ... done
  Stored in directory: C:\Users\Administrator\AppData\Local\pip\Cache\wheels\37\
ef\32\563bbf605a7a60268d6585a942660e77ab6abf40d43c1abf3a
Successfully built virtualenvwrapper-win
Installing collected packages: virtualenv, virtualenvwrapper-win
Successfully installed virtualenv-15.1.0 virtualenvwrapper-win-1.2.2
#建立虚拟环境文件夹，可以先cd目标文件夹下面在建，安装完成后即为激活状态
C:\Users\Administrator\Desktop\testdir\Scripts>mkvirtualenv testdir2
 C:\Users\Administrator\Envs is not a directory, creating
Using base prefix 'd:\\python'
New python executable in C:\Users\Administrator\Envs\testdir2\Scripts\python.exe

Installing setuptools, pip, wheel...done.
#退出虚拟环境
(testdir2) C:\Users\Administrator\Desktop\testdir\Scripts>deactivate
#workon查看系统下的所有虚拟环境
C:\Users\Administrator\Desktop\testdir\Scripts>workon

Pass a name to activate one of the following virtualenvs:
==============================================================================
testdir2
#workon到某个虚拟环境
C:\Users\Administrator\Desktop\testdir\Scripts>workon testdir2
#退出虚拟环境
(testdir2) C:\Users\Administrator\Desktop\testdir\Scripts>deactivate

#workon选择的虚拟环境文件夹
C:\Users\Administrator\Desktop\testdir\Scripts>workon testdir2
(testdir2) C:\Users\Administrator\Desktop\testdir\Scripts>pip install requests
Collecting requests
  Downloading requests-2.18.4-py2.py3-none-any.whl (88kB)
    46% |██████████████▊                 | 40kB 292kB/s eta 0:00:
    57% |██████████████████▌             | 51kB 308kB/s eta 0
    69% |██████████████████████▏         | 61kB 367kB/s e
    80% |█████████████████████████▉      | 71kB 389kB/
    92% |█████████████████████████████▌  | 81kB 43
    100% |████████████████████████████████| 92kB
 451kB/s
Installing collected packages: chardet, idna, certifi, urllib3, requests
Successfully installed certifi-2017.7.27.1 chardet-3.0.4 idna-2.6 requests-2.18.
4 urllib3-1.22
#查看安装的包
(testdir2) C:\Users\Administrator\Desktop\testdir\Scripts>pip list
DEPRECATION: The default format will switch to columns in the future. You can us
e --format=(legacy|columns) (or define a format=(legacy|columns) in your pip.con
f under the [list] section) to disable this warning.
certifi (2017.7.27.1)
chardet (3.0.4)
idna (2.6)
pip (9.0.1)
requests (2.18.4)
setuptools (36.5.0)
urllib3 (1.22)
virtualenv (15.1.0)
virtualenvwrapper-win (1.2.2)
wheel (0.30.0)

#卸载requests包
(testdir2) C:\Users\Administrator\Desktop\testdir\Scripts>pip uninstall requests

Uninstalling requests-2.18.4:

Proceed (y/n)? y
  Successfully uninstalled requests-2.18.4