python练习4

#列出指定目录下的项目
import os
import os.path
import sys


def list_dir():
    _dir = sys.argv
    if len(_dir) == 1:
        _dir = '.'
    else:
        _dir = _dir[1]
    L =[x for x in os.listdir(_dir)]
    print(L)



if __name__ == '__main__':
    list_dir()

#正则表达式
import re

re_name = re.compile('([0-9a-zA-Z. <>]+)@([0-9a-zA-Z.]+)')
re_name_sub = re.compile('<([a-zA-Z ]+)> ([a-zA-Z ]+)')
def name_of_email(addr):
    name = re.match(re_name,addr).groups()[0]
    if re.match(re_name_sub,name) != None:
        return re.match(re_name_sub,name).groups()[0]
    return name


#print(name_of_email('<Tom Paris> tom@voyager.org'))
# 测试:
assert name_of_email('<Tom Paris> tom@voyager.org') == 'Tom Paris'
assert name_of_email('tom@voyager.org') == 'tom'
print('ok')