Answer:
import random
def shuffle_if_even(cards):
"""
Shuffle a deck of cards if the top card is even.
Args:
cards (list): The deck of cards to shuffle.
Returns:
None: The function does not return any value.
"""
if len(cards) > 1:
top_card = cards[-1]
if top_card.num in [2, 4, 6, 8, 10, "Q", "A"]:
random.shuffle(cards)