def func():
total = 0
while True:
pet = input("What pet do you have? ")
if pet == "rock":
return
total += 1
print("You have a {} with a total of {} pet(s)".format(pet, total))
func()
We wrapped our code in a function so that whenever the user enters rock, we can simply return and exit the function. If you have any other questions, I'll do my best to answer them.