要求:生成一个规定字符个数和数字个数的随机密码
from random import Random
import string
def random_str(numLength = 4, stringLength = 6):
str = ''
letters = string.letters
digits = string.digits
random = Random()
for i in range(stringLength):
str += letters[random.randint(0,len(letters)-1)]
for i in range(numLength):
str += digits[random.randint(0,len(digits)-1)]
str = list(str)
random.shuffle(str)
return ''.join(str)
print random_str()