import os,fnmatch,datetime,time

def all_files(root,pattern='*',single_level=False,yield_folders=False):

    patterns = pattern.split(';')

    for path,subirs,files in os.walk(root):

        if yield_folders:

            files.extend(subirs)

        files.sort()

        for name in files:

            for pattern in patterns:

                if fnmatch.fnmatch(name,pattern):

                    yield os.path.join(path,name)

                    break

        if single_level:

            break

for path in all_files("E:/",'*.rar'):

    print(path)

    create_file_time = os.path.getctime(path) #文件创建的时间戳

    ltime = time.localtime(create_file_time)

    timestr = time.strftime("%Y-%m-%d %H:%M:%S",ltime)  #验证时间戳转换为年月日格式，测试用

    print(timestr)

    age_in_days = ((time.time()-create_file_time)/(60*60*24))

    if age_in_days > 20:

        os.remove(path)

        print('remove file: %s' % path)

    else:

        print("文件创建天数小于20天")