userName=input("Enter a username:")
while len(userName) < 2 or len(userName) > 10:
    userName = input("Enter a username:")

validPassword = False
while validPassword == False:
    password = input("Enter a new password:")
    if password.lower() == password:
        print("You password must contain an uppper case character")
    elif password.upper() == password:
        print("You password must contain a lower case character")
    else:
        print("Password case correct")
        validPassword = True

print("\n=== Menu ===")
print("1. Add Students")
print("2. Search Students")
print("3. Sort Students")
print("4. Log out\n")

validChoice = False

while validChoice == False:
    choice = input("Enter an option 1-4: ")
    if choice in ["1", "2", "3", "4"]:
        print("You have chosen option " + choice)
        validChoice = True