Linux查找目录下文件包含关键字

#coding=utf-8
import os
import re
c_dir = []
txt_files = []
def search_files(dir,key):
    dir = dir
    c_dir.append(dir)
    os.chdir(dir)
    all_files = os.listdir(os.curdir)
    keys = re.compile(r"%s" % key)
    for each_file in all_files:
        if os.path.isfile(each_file):
            f = open(each_file,'r')
            details = f.read()
            if keys.findall(details):
                txt_files.append(os.path.join(os.getcwd(),each_file))
        elif os.path.isdir(each_file):
            search_files(os.path.join(os.getcwd(),each_file),key)
            os.chdir(os.pardir)
dir = raw_input("请输入查看的目录：")
key = raw_input("请输入要查找的关键字")
search_files(dir,key)
print(txt_files)