Oython password checker

def passwordIsOk (code):
    special_char = "$#%*"
    okLower = False
    okNumber = False
    okUpper = False
    okSpecial = False

    if len(code) < 10:
        print("Short password")
        return False

    if " " in code:
        print("Space in password.")
        return False

    for letter in code:
        if letter.isupper():
            okUpper = True
        elif letter.islower():
            okLower = True
        elif letter.isdigit():
            okNumber = True
        elif letter in special_char:
            okSpecial = True

    if not okLower:
        print("No lowercase letter.")
    if not okNumber:
        print("No digit.")
    if not okUpper:
        print("No uppercase letter.")
    if not okSpecial:
        print("No special character.")

    return okUpper and okLower and okNumber and okSpecial

while True:
    userPassword = input("Please enter a password: ")
    valid = passwordIsOk( userPassword )
    if not valid:
        print ( "This password is invalid, please try again" )
        continue
    else:
        print ("Your password is", userPassword)
        break