python判断文件是否存在目录中

##支持排除文件和目录
#!/usr/bin/python
#coding:utf-8
import os

def list_file(file_name):
    data = []
    file_name = file_name
    with open(file_name,'r') as f:
        for line in f.readlines():
            line = line.strip('\n')
            data.append(line)
    return data

def list_dir(dir_name):
    data = []
    dir_name = dir_name
    for root,dirs,files in os.walk(dir_name):
#exclude.txt写入需要排除比较的目录
        for rdir in open("./exclude.txt"):
            rdir = rdir.strip('\n')
            if rdir in dirs:
                dirs.remove(rdir)
        #print dirs
        for filename in files:
            filepath = os.path.join(root,filename)
            #f.write(filepath+'\n')
            data.append(filepath)
    return data
if __name__ == "__main__":
    keep_file = 'file.txt'
    local_dir = '/opt/app/fileops/testdir/'
    keep_path = list_file(keep_file)
    local_path = list_dir(local_dir)
    for i in local_path:
        if i not in keep_path:
           #print os.path.getctime(i)
           #os.remove(i)
           print i