Python检测密码是否符合要求，大小写字母数字长度等密码必须包含超过8个字符，且不超过16个字符。密码必须包含至少一个数字、一个大写字母和一个小写字母。密码必须包含多个非字母数字字符。

要使密码更强大，它需要满足以下四个规则：

1. . 密码必须包含超过8个字符，且不超过16个字符。“

提示：查找密码字符串的长度，您应该使用len（）方法。

1. 密码必须包含至少一个数字、一个大写字母和一个小写字母。
2. 密码必须包含多个非字母数字字符。

第一种方式是使用函数

1. if len(a) > 16 or len(a) < 8:
       print(a + "is not of valid length " + str(len(a)))
       isOk = 0
   else:
       print(a + "is of valid length " + str(len(a)))
   print("Check rule 2")
   # Set the function
   lowercases = 0
   uppercases = 0
   digits = 0
   alpha = 0
   # Find, detect output upper and lower case alphanumeric
   for char in a:
       if char.islower():
           lowercases += 1
       elif char.isupper():
           uppercases += 1
       elif char.isdigit():
           digits += 1
   print("Number of lowercase is: " + str(lowercases))
   print("Number of uppercase is: " + str(uppercases))
   print("Number of digit is: " + str(digits))
   if lowercases == 0 or uppercases == 0 or digits == 0:
       print(a + " does not contain enough of each type of character")
       isOk = 0
   else:
       print(a + " contain enough of each type of character")
   print("check rule 3")
   # Detecting special characters
   if alpha != 0:
       print(a + " contain non-alpha-numeric")
   else:
       print(a + " does not contain non-alphanumeric")
       isOk = 0
   print("Check for all the rules")
   if isOk:
       print("Overall " + a + " isvalid")

   第二种最简单的方法

2. def password_check(passwd):
       SpecialSym = ['$', '@', '#', '%', '@', '!', '&', '=', '+', '_', '-', '$', '/', ]
       val = True
   # check the length
       if len(passwd) < 8:
           print('length should be at > 8')
           val = False
       else:
           print('length is than 8 ')
   
       if len(passwd) > 16:
           print('length should be not be least than 16')
           val = False
       else:
           print('length is least than 16')
   # check the number
       if not any(char.isdigit() for char in passwd):
           print('Password should have at least one numeral')
           val = False
       else:
           print('password have least one numeral')
   
   # check the uppercase
       if not any(char.isupper() for char in passwd):
           print('Password should have at least one uppercase letter')
           val = False
       else:
           print('Password have at least one uppercase letter')
   # check the lowercase
       if not any(char.islower() for char in passwd):
           print('Password should have at least one lowercase letter')
           val = False
       else:
           print('Password have least one lowercase letter')
   # check the Special characters
       if not any(char in SpecialSym for char in passwd):
           print('Password should have at least one of the symbols $@#')
           val = False
       else:
           print('Password have least one of the symbols $@#')
       if val:
           return val
   
   
   def main():
   
       if password_check(password):
   
           print('Password is valid')
       else:
           print("Invalid Password !!")
   
   
   # Driver Code
   if __name__ == '__main__':
       password = input('Enter your password: ')
       main()