[cb321]

cython --annotate is an ok way to learn the whys & whereabouts of the rather hairy CPython API. That gives you an HTML page you can click on to expand your python code into equivalent-ish C API calls. Darker yellow means more calls, too. So, it's not a terrible start to do static analysis to guide optimization, but a combination score (with a run-time profile) would be even better.

I believe there was a time very early on (like 2003) when there was discussion about maybe including Pyrex in CPython proper to get a more Common-Lisp like gradually typed system. (I mostly recall some comment of Greg's along the lines of being intimidated by such. I'm not sure how seriously the idea was entertained by PyCore.)