多版本python pip报错Fatal error in launcher: Unable to create process using解决

由于python即装了python2后又装了python3.

隔了一段时间，发现pip不合适了，pip install安装提示Fatal error in launcher: Unable to create process using

切换到我们安装python的script目录，如cmd C:\Python27\Scripts，执行命令

                             python2 -m pip install --upgrade pip

同理，python3执行命令

                             python3 -m pip install --upgrade pip

可发现pip库已有更新

PS：python2 为C:\Python27下的python2.exe（已重命名），python3同理。