Skip the learning phase, go straight to useful work. Sometime ago I had to render some maps with Mapnik (http://mapnik.org) which is driven by Python scripts. I didn't know any Python, so I just pasted an example from the 'net and started reworking it to suit my needs, experimenting and reading docs whenever I got stumped. Quickly picked up enough Python to write my own scripts, solve other tasks. For me it's the only way to learn.