How can python2 and python3 exist at the same time?

Install python2 and python3 in the operating system and 


modify the configuration:


go to the installation directory of python3, find the python.exe file, rename it to python3.exe


, enter python3 in cmd, and you can see the python3 version displayed  

Copy a python3.exe file, then modify it to python.exe, then in cmd

You can see the version of python3 that appears on pip -V