Recursive Find File utility

findefile.py

import os

def findfiles(files, test = lambda path: os.path.splitext(path)[1].lower() == '.xlsx'):

    if isinstance(files, str):
        files = [files]

    for path in files:
        if os.path.isdir(path):
            for root, dirs, files in os.walk(path):
                for f in files:
                    if test(f):
                        yield os.path.join(root, f)
        else:
            if os.path.exists(path) and test(path):
                yield path