Which Python tool can you recommend to parse programming languages? It should allow for a readable representation of the language grammar inside the source, and it should be able to scale to complicated languages (something with a grammar as complex as e.g. Python itself).
When I search, I mostly find pyparsing, which I will be evaluating, but of course I'm interested in other alternatives.
Edit: Bonus points if it comes with good error reporting and source code locations attached to syntax tree elements.