You could try renaming that
pip.py to something else.
There is a library called pip somewhere on your system (and it may also be bundled within pip.exe). That is different from the "entry point" script that actually runs pip from the command line. When you run pip, it will try to import the library called pip. If there is a script called pip.py in the Scripts directory (representing the entry-point script, not the library), it may import that instead of the real library. If this is indeed the problem, renaming pip.py to something else will remove the name conflict and allow pip to properly import the library it needs.
I'm not sure how you wound up with pip.py in your Scripts directory in the first place. I don't think it should be there. My Python installation on Windows doesn't have it.