pip upgrade error: raise ValueError(msg)ValueError: Unable to find resource t64.exe in package solution

1. Problem background

      When using python.exe -m pip install --upgrade pip to upgrade pip, the following problem occurs: ValueError: Unable to find resource t64.exe in package pip._vendor.distlib. . . . . .

 2. Solution

         Use the following command to re-upgrade -

python -m pip install --user --upgrade pip