alt Hacker NewsNever, ever, ever transform URIs and paths by string manipulation. If you think pulling in a library for this is overkill, it is not.
(Lesson learned from trying to quickly write my own function to make ".." to go back one URL segment that took 3 hours and discovering the URI spec contradicts my intuition depending on whether the URI is a URL or filesystem path.)
I don't believe Python's urllib has a function that takes what HTTP terms an "origin-form" (an absolute path with possibly a query attached to it with "?") and parses it apart.
Still, the RFC 9112 that defines HTTP/1.1 basics requires that, for the purposes of URI reconstruction, "if there is no Host header field or if its field value is empty or invalid, the target URI's authority component is empty."