Completely solve the problem that pip in the anaconda virtual environment is a global pip download package automatically to the base environment instead of the virtual environment No module named _abc error resolution

Delete PYTHONHOME        C:\ProgramData\Anaconda3    in system variables       

At the same time, you need to add the path of the Lib/site-package of the virtual environment to the system variable Path , otherwise it will still report an error that there is no _abc module