完整的错误提示:

C:\Users\yyy>ipython3
Fatal error in launcher: Unable to create process using '"c:\users\yyy\appdata\local\programs\python\python37\python.exe" "C:\Users\yyy\AppData\Local\Programs\Python\Python37\Scripts\ipython3.exe" '

同时安装python2 和 python3时

对安装目录中的 python改名为python2 和 python3后,

导致不能找到原来的python文件造成的:'"c:\users\yyy\appdata\local\programs\python\python37\python.exe"

解决办法: 在改名前先复制一份python.exe出来,然后再把复制的exe更名为python2和python3