Minimum Characters required to create a Strong Password

from string import ascii_uppercase, ascii_lowercase

def strongpass(n, password): # n -> length of 'password'; password ==> string containing the password
    no_to_add = 0
    upper, lower, no, spl = (False,)*4

    for i in password:
        if i in ascii_uppercase:
            upper = True
        elif i in ascii_lowercase:
            lower = True
        elif i in "1234567890":
            no = True
        elif i in "!@#$%^&*()-+":
            spl = True

    L1 = [upper, lower, no, spl]
    no_to_add += L1.count(False)

    if (n + no_to_add) >= 6 :
        return no_to_add
    else:
        return no_to_add + (6 - (n + no_to_add))

val = strongpass(1, "9")
print(val)