Some Python releases are deprecated, this is the list of the latest available modules for Maya 2018-2022:
Add folder path to MAYA_MODULE_PATH variable. It will work for all Maya versions. Check p4python.mod file for the details
If you don't want to download all the versions, you can just copy P4.py and P4API.pyd directly to any folder in your PYTHONPATH environment. The *.pyd file should match Maya's Python version.
from P4 import P4
p4 = P4()
p4.connect()
Check P4 Documentation for more info