traverse files under one folder recursively

tranverse.py

#!/usr/bin/python

import os

def traverse_dir_recur(dir):
    import os
    l = os.listdir(dir)
    for d in l:
        if os.path.isdir(dir + '/' + d):
            traverse_dir_recur(dir + '/' + d + "/")
        else:
            f = open(dir + '/' + d, 'r')
            try:
                line = f.read()
                # do something
                # bytes(line, 'utf-8').decode('utf-8')
            except UnicodeDecodeError:
                print(dir + '/' + d)
traverse_dir_recur('/path/to/folder')