check password

import re
i = input('Pls input you password')
n = len(i)
num1 = re.compile(r'[0-9]+')
big = re.compile(r'[A-Z]+')
small = re.compile(r'[a-z]+')
if n > 8 :
    if num1.search(i):
        if big.search(i):
            if small.search(i):
                print("password is ok")
            else:
                print("password not have small char")
        else:
            print("password not have big char")
    else:
        print("password not have number")
else:
    print("password must bigger than 8")