Why should two equal-ranked cards refuse to stay tied? A suit is the category carried by a card—spades, hearts, diamonds, or clubs—and it can provide a second ordering after rank. In the compact poker notation used here, every card has two symbols: a rank and a suit, so 10♥ becomes T♥. section 4.10
Suit order is not a law of nature. For descending card sorting, the requested convention is spades, hearts, diamonds, clubs; a different game can reasonably choose another convention. State that policy instead of hoping a sorting function—or an AI—will infer it from the word “cards.” section 4.12 section 4.10
Suits do several small but important jobs in card-hand processing:
- Break rank ties while sorting a hand, after ranks such as A, K, Q, and T have established the primary order. section 4.12 section 4.10
- Represent the common-suit condition of a flush: five cards share one suit. A successful check can return that suit rather than merely True. section 4.14
- Accept either ASCII suit letters S, H, D, C or Unicode symbols ♠, ♥, ♦, ♣, then normalize or recognize both forms. section 4.14 section 4.10
A sorting key can look right and still reverse the policy
A candidate sorter maps ♠ to 1, ♥ to 2, ♦ to 3, and ♣ to 4, then sorts tuple keys in reverse. That puts clubs ahead of spades for equal ranks—the opposite of the stated spades-first order. The mapping and the sort direction must agree; code that runs is not automatically code that honors the rule. section 4.12
def sort_hand(hand):
# Create a mapping from card rank to numeric value
rank_to_value = { #1
'2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8,
'9': 9, 'T': 10, 'J': 11, 'Q': 12, 'K': 13, 'A': 14 }
# Create a mapping from suit to numeric value
suit_to_value = {'♠': 1, '♥': 2, '♦': 3, '♣': 4} #2
# Split the hand into individual cards
cards = hand.split()
# Sort the cards by rank and then suit
sorted_cards = sorted(cards,
key=lambda x: (rank_to_value[x[0]], suit_to_value[x[1]]),
reverse=True)
# Return the sorted hand as a string
return ' '.join(sorted_cards)
# Test the function
hand = "A♥ 4♠ 4♥ K♦ 3♠"
print(sort_hand(hand)) # should print "A♥ K♦ 4♥ 4♠ 3♠"
Inspect the rank-and-suit tuple key: it makes the hidden interaction between numeric suit values and reverse sorting visible. section 4.12
For a flush, the suit is useful information to preserve. A regular expression can capture the repeated suit character and return it on success, while returning False when even one card differs. That result can then combine with a straight check to recognize a straight flush. section 4.14
