如何找到一个目录下所有.txt文件

import os

root = "H:\\ab123"

def findtxt(path, ret):

    """Finding the *.txt file in specify path"""

    filelist = os.listdir(path)

    for filename in filelist:

        de_path = os.path.join(path, filename)

        if os.path.isfile(de_path):

            if de_path.endswith(".txt"): #Specify to find the txt file.

                ret.append(de_path)

        else:

            findtxt(de_path, ret)

ret = []

findtxt(root, ret)

for path in ret:

    print(path)