python使用正则表达式检测密码强度源码分享

#encoding=utf-8
#-------------------------------------------------------------------------------
# name:        模块1
# purpose:
#
# author:      administrator
#
# created:     10-06-2014
# copyright:   (c) administrator 2014
# licence:     <your licence>
#-------------------------------------------------------------------------------
import re
def checklen(pwd):
    return len(pwd)>=8
def checkcontainupper(pwd):
    pattern = re.compile('[a-z]+')
    match = pattern.findall(pwd)
    if match:
        return true
    else:
        return false
def checkcontainnum(pwd):
    pattern = re.compile('[0-9]+')
    match = pattern.findall(pwd)
    if match:
        return true
    else:
        return false
def checkcontainlower(pwd):
    pattern = re.compile('[a-z]+')
    match = pattern.findall(pwd)
    if match:
        return true
    else:
       return false
def checksymbol(pwd):
    pattern = re.compile('([^a-z0-9a-z])+')
    match = pattern.findall(pwd)
    if match:
        return true
    else:
        return false
def checkpassword(pwd):
    #判断密码长度是否合法
    lenok=checklen(pwd)
    #判断是否包含大写字母
    upperok=checkcontainupper(pwd)
    #判断是否包含小写字母
    lowerok=checkcontainlower(pwd)
    #判断是否包含数字
    numok=checkcontainnum(pwd)
    #判断是否包含符号
    symbolok=checksymbol(pwd)
    print(lenok)
    print(upperok)
    print(lowerok)
    print(numok)
    print(symbolok)
    return (lenok and upperok and lowerok and numok and symbolok)

def main():
    if checkpassword('helloworld#123'):
        print('检测通过')
    else:
        print('检测未通过')

if __name__ == '__main__':
    main()

平时用正则不多，不知道怎么写一个正则满足要求，用了比较笨的办法，谁知道一句正则检验的请赐教!