Methods changed in different Git versions

Given two different versions of a source file, determine the mapping between methods in those two files. The input to your program should be two different versions of a file written in either python or java language (you can select one of the two languages). For simplicity consider that each file contains only one class consisting of a set of methods.
Methods can be added or deleted in the new version, method in the old version can be renamed or modified (e.g., lines added, deleted, parameters or return type of the methods can also be changed) in the new version.