python os.join

https://www.geeksforgeeks.org/python-os-path-join-method/

https://stackoverflow.com/questions/45410508/python-requests-ca-certificates-as-a-string 

os.path.join() method in Python join one or more path components intelligently. This method concatenates various path components with exactly one directory separator (‘/’) following each non-empty part except the last path component. If the last path component to be joined is empty then a directory separator (‘/’) is put at the end. 

If a path component represents an absolute path, then all previous components joined are discarded and joining continues from the absolute path component.