Python - Python2与Python3合理共存Windows平台

Install Python2 and Python3

Python 2.7.13 - Windows x86-64 MSI installerPython 3.6.0 - Windows x86-64 executable installer Note: For Python 3.3 and later, select the option "Install launcher for all users(recommended)".

Set Environment Variables Sample:C:\Python27;C:\Python27\Scripts;C:\Python27\Lib\site-packages;C:\Python36;C:\Python36\Scripts;C:\Python36\Lib\site-packages;

Check system variables - path : Run the commond >set path and check the output.

Python Launcher for Windows Version

Python Launcher for Windows Version

  >py -2 Python 2.7.12 (v2.7.12:d33e0cf91556, Jun 27 2016, 15:24:40) [MSC v.1500 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> >py -3 Python 3.6.0 (v3.6.0:41df79263a11, Dec 23 2016, 08:06:12) [MSC v.1900 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>>

Run an sample

Method 1 : python or py

>python --version Python 2.7.13 >py --version Python 3.6.0

Method 2 : py -2 or py -3

  >type HelloWorld-py2.py print 'Hello World! Hello Python!' > >py -2 HelloWorld-py2.py Hello World! Hello Python! >type HelloWorld-py3.py print ('Hello World! Hello Python!') > >py -3 HelloWorld-py3.py Hello World! Hello Python! >

Note:py -2.7 HelloWorld-py2.py and py -3.6 HelloWorld-py3.py are recommended.

Method 3 : Specify the Python version in a script

>type HelloWorld-py2.py #! python2.7 print 'Hello World! Hello Python!' > >py HelloWorld-py2.py Hello World! Hello Python! >type HelloWorld-py3.py #! python3.6 print ('Hello World! Hello Python!') > >py HelloWorld-py3.py Hello World! Hello Python! >

pip2 and pip3

Install Python2 Package: pip2 install <Package_name> or py -2 -m pip install <Package_name> Install Python3 Package: pip3 install <Package_name> or py -3 -m pip install <Package_name>

  >pip2 --version pip 9.0.1 from c:\python27\lib\site-packages (python 2.7) >pip3 --version pip 9.0.1 from c:\python36\lib\site-packages (python 3.6)

Run an sample

  >pip3 list --format=legacy pip (9.0.1) setuptools (28.8.0) >pip3 install requests --proxy=10.144.1.10:8080 Collecting requests Downloading requests-2.13.0-py2.py3-none-any.whl (584kB) 100% |████████████████████████████████| 593kB 137kB/s Installing collected packages: requests Successfully installed requests-2.13.0 >pip3 list --format=legacy pip (9.0.1) requests (2.13.0) setuptools (28.8.0)

py help

  $ py -h Python Launcher for Windows Version 3.6.150.1013 usage: py [ launcher-arguments ] [ python-arguments ] script [ script-arguments ] Launcher arguments: -2 : Launch the latest Python 2.x version -3 : Launch the latest Python 3.x version -X.Y : Launch the specified Python version -X.Y-32: Launch the specified 32bit Python version