Python for Everybody 5.2 assignment

[baba04201]

Hey guys- I'm on my last assignment for Python and I need some expert assistance please.

This is the assignment:
5.2 Write a program that repeatedly prompts a user for integer numbers until the user enters 'done'. Once 'done' is entered, print out the largest and smallest of the numbers. If the user enters anything other than a valid number catch it with a try/except and put out an appropriate message and ignore the number. Enter 7, 2, bob, 10, and 4 and match the output below.

This is my code:

largest = None
smallest = None
while True:
    try:
        num = raw_input("Enter a number: ")
        if num == "done":
            break
        print (num)
        num = int(num)
        if largest is None or largest < num:
            largest = num
        elif smallest is None or smallest > num:
             smallest = num
    except ValueError:
        print("Please, enter only numbers.")

print ("Maximum", largest)
print ("Minimum", smallest)

This is the Desired output:
Invalid input
Maximum is 10
Minimum is 2

This is my output:
7 ← Mismatch
2
bob
Please, enter only numbers.
10
4
Maximum 10
Minimum 2

I need help please.