One problem: Did not provide a command
①pip is a .exe executable file, type in cmd can be resolved pip.exe
② environment variable configuration, plus behind PATHEXT editor; .EXE (note the semicolon in English)
③ pip window find the folder that contains directory, folder address bar enter cmd carriage return, and then open the input pip
④ open cmd, cd to the directory where the pip, such as D: \ test \ python3 \ Scripts, then re-enter the pip
Second problem: ModuleNotFoundError: No module named 'pip'
Because this error leads to pip found,
May be performed first python -m ensurepip then execute python -m pip install --upgrade pip can be updated