Renaming of functions with preservation of backward compatibility

Question

I refactor my old code and want to change the names of functions in accordance with pep8. But I want to maintain backward compatibility with old parts of system (a complete refa

Answer 1

While the other answers are definitely true, it could be useful to rename the function to the new name and create an old one which emits a warning:

def func_new(a):
    do_stuff()

def funcOld(a):
    import warnings
    warnings.warn("funcOld should not be called any longer.")
    return func_new(a)