Learning Python: simple functions to write [closed]

Question

I'm starting to learn Python, and I would love to "test" myself with a series of simple challenges. Things like "write a function that sorts a list alphabetically", "write a function to convert underscore-separated strings into camel-case", etc. I'm basically looking for a series of problems to work my way through as I wrap my head around Python (think CS 101 homework assignments): either a list of 10-15 ideas, or a link to one.

Bonus points for stuff that specifically makes use Python's unique features like tuples, generators, etc. A nod in the right direction for each problem wouldn't go amiss, either.

Answer 1

Beginner-level:

http://codingbat.com/python

All other levels:

http://projecteuler.net/