Finding a program's location on disk, while it runs

I wanted to know, Lets assume, I made a program called foo.c, and I want to save in some variable, or really, anywhere, the address in the memory, where the program sits. How do I do that?

(Would like to do that, to generate a high level randomizing algorithm)

P.S That doesn't have to be in C, really anywhere, preferably in Python / C .

Thanks.