Question

我想验证用户的密码是否为：

由8个字符组成
由数字和字母组成
至少一个大字和一个数字
它应该包含$或！还是？
订单无关紧要

我的代码是：

r.match(r'([A-Z]+)([a-z])([0-9]+)($|?|!){8}',password)

这是正确答案吗？我不知道如何指定，该顺序在正则表达式中无关紧要。

EDITED 使用一些建议我编辑了我的代码：

m = re.compile(r'^(?=.*\d)(?=.*[A-Z])(?=.*[\$|\?\!])[A-Za-z\d$!&]{8}$')
m.match('adwA12f!')
<_sre.SRE_Match object; span=(0, 8), match='adwA12f!'>

如果有可能澄清，你能取悦，究竟是什么“？=。”正则表达式意味着。

Answer 1

这似乎在IDLE 2.7.9中进行了测试。请记住，这只匹配8个字符

^(?=.*[!$?])(?=.*[a-z])(?=.*[A-Z]).{8}$

import re
p = re.compile('^(?=.*[!$?])(?=.*[a-z])(?=.*[A-Z]).{8}$')
test_str = 'a2Cd$F!8'
if re.search(p, test_str):
    print('string matched')

输出：

string matched

?=是一个先行断言;建议您阅读本网站："Lookahead Assertion"

.匹配除换行符之外的任何字符;由于您有方括号，.仅限于[]中定义的内容;也称为原子分组。

Answer 2

我想明显的非正则表达方式是：

symbols = '$!?'
if (len(pwd) >= 8 and
        any(c.isdigit() for c in pwd) and
        any(c.isupper() for c in pwd) and
        any(c in symbols for c in pwd) and
        all(c.isalnum() or c in symbols for c in pwd)):
    print('good password')
else:
    print('bad password')

你没有说，但我认为你也至少要一个小写。如果是这样，也添加这个子句

any(c.islower() for c in pwd)

Answer 3

至少在我的系统上，不使用re进行检查的速度要快一些。此外，随着密码长度的增加，速度差异似乎变得更加明显。

import re
import timeit

passwords_varied = ("kk", "999999999999999999999999", "kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk", "gkrDsh!2", "gjtlssssssssssssssssfsdg43ggw3fa2adada2fagaa2adajjjjjjjjjjjjjjjkhjkhjkhjkd45!", "kit43MM?", "fkthrej!", "483kkED!")

passwords_8chars = ("hktj33cD", "!?gk329s", "fkrK44?a", "dlekAS2$", "??ffD913")

def check1(s):
    return len(s) == 8 and \
    any(x.isdigit() for x in s) and \
    any(x in ("$","!","?") for x in s) and \
    any(x.isupper() for x in s)

def check2(s):
    if len(s) == 8 and \
    re.search(r"\d", s) and  \
    re.search(r"[$!?]", s) and \
    re.search(r"[A-Z]", s):
        return True
    return False

def run1(passwords):
    for password in passwords:
        check1(password) 

def run2(passwords):
    for password in passwords:
        check2(password)


def main():
    print ("---- list comprehension approach ----")
    print ("varying length passwords")
    print(timeit.timeit("run1(passwords_varied)", setup="from __main__ import run1, passwords_varied", number=100000))
    print ("correct length passwords")
    print(timeit.timeit("run1(passwords_8chars)", setup="from __main__ import run1, passwords_8chars", number=100000))
    print ""
    print "---- 're' approach ----"
    print ("varying length passwords")
    print(timeit.timeit("run2(passwords_varied)", setup="from __main__ import run2, passwords_varied", number=100000))
    print "correct length passwords"
    print(timeit.timeit("run2(passwords_8chars)", setup="from __main__ import run2, passwords_8chars", number=100000))


if __name__ == '__main__':
    main()


"""
---- list comprehension approach ----
varying length passwords
2.69666814804
correct length passwords
3.31486010551

---- 're' approach ----
varying length passwords
3.27806806564
correct length passwords
4.286420106

"""

Python 3中密码的正则表达式

3 个答案: