python question

The second function you will write should be called cardType. Your function should take one (1) argument, an integer representing a card type. The function should return one (1) string. The return string should contain one of three possible values: Visa, MasterCard, Discover Card. The value should be determined according to the following rules. Credit card numbers follow a standard system. For example, Visa, MasterCard, and Discover Card all have 16 digits, and the first digit serves to indicate the card brand. All Visa cards start with a 4; MasterCard cards always starts with a 5; and Discover cards start with a 6. For this lab, you may assume your function will only be passed a 4, 5, or 6.

Testing: Create your own test cases.