Lesson 25 — Ultimate: mini URL router

Boss level: URLs with parameters

Real URLs carry data: /user/7 means "user number 7". Django writes this as path("user/<int:id>/", view). Underneath, it is a regular expression (a text pattern): (\d+) matches one or more digits and captures them, and m.groups() hands the captured text to the view.

re.match(r"^/user/(\d+)$", "/user/7").groups()   # ('7',)

Note: the exercise runs in your browser without Django installed, so it is a small plain-Python simulation of what Django does for you.

Why it matters: every framework starts with routing — now you know how it really works.