python snippet

[rbisping]

hey, im needing a code snippet probably in python to parse a text file
and do a single character replace based on a couple of parameters.

I need to be looking through the file for either T1 or T0 and replace
the character E with A if after a T1 and B after a T0

It should be a simple snippet but not having much python programing
experience and not wanting to do it in C instead I was hoping someone
would be able to toss me a code snippet to acomplish it.