pythonフォルダを巡ってフォルダの接尾辞がpyのファイルを見つけます

#coding=utf-8
import os
class Solution:
    def __init__(self):
        self.dirPath = []

    def numberOfCode(self,path):
        for dir in os.listdir(path):
            childDir = os.path.join(path,dir)
            if os.path.isdir(childDir):
                self.numberOfCode(childDir)
            else:
                if childDir[-2:] == "py":
                    self.dirPath.append(childDir)
        return self.dirPath

    def setCode(self):
        with open("/home/code.py","ab+") as f:
            for file in self.dirPath:
                content = open(file,"r").read()
                f.write(content)
s = Solution()
s.numberOfCode("/home/py/")
s.setCode()