Text-based blackjack in python

Question

This is code for a text-based game of Blackjack.

I would also like advice on how can I implement a betting system in this program. For example starting with an amount of chips and choosing how much of them to bet.

import random
card_suit = ['Hearts', 'Diamonds', 'Clubs', 'Spades']
card_value = ['Ace', '2', '3', '4', '5', '6', '7', '8', '9', '10', 'Jack', 'Queen', 'King']
deck = [(value, suit) for suit in card_suit for value in card_value]
def card_points(card):
 if card[0] in ['Jack', 'Queen', 'King']:
 return 10
 elif card[0] == 'Ace':
 return 11
 else:
 return int(card[0])
 
random.shuffle(deck)
player_cards = [deck.pop(), deck.pop()]
dealer_cards = [deck.pop()]
player_points = sum(card_points(card) for card in player_cards)
dealer_points = sum(card_points(card) for card in dealer_cards)
def points(dealer_points, player_points, dealer_cards, player_cards):
 while dealer_points < 17:
 new_card = deck.pop()
 dealer_cards.append(new_card)
 dealer_points += card_points(new_card)
 print("Dealer's Cards:", dealer_cards)
 print("Dealer's Points:", dealer_points)
 print("\n")
while True:
 print("Dealer's Cards:", dealer_cards)
 print("Dealer's Points:", dealer_points)
 print("\n")
 print("Player's Cards:", player_cards)
 print("Player's Points:", player_points)
 print("\n")
 decision = input('What will you do? ["hit" for a new card, "stand" to end the game]: ').lower()
 if decision == "hit":
 new_card = deck.pop()
 player_cards.append(new_card)
 player_points = sum(card_points(card) for card in player_cards)
 if player_points > 21:
 print("Dealer's Cards:", dealer_cards)
 print("Dealer's Points:", dealer_points)
 print("Player's Cards:", player_cards)
 print("Player's Points:", player_points)
 print("Dealer wins (player has more than 21 points)")
 break
 elif decision == "stand":
 while dealer_points < 17:
 new_card = deck.pop()
 dealer_cards.append(new_card)
 dealer_points += card_points(new_card)
 print("Dealer's Cards:", dealer_cards)
 print("Dealer's Points:", dealer_points)
 print("Player's Cards:", player_cards)
 print("Player's Points:", player_points)
 if player_points > 21:
 print("Dealer wins (player has more than 21 points).")
 elif dealer_points > 21:
 print("You win! (dealer has more than 21 points)")
 elif player_points > dealer_points:
 print("You win! (you have more points than the dealer)")
 elif player_points < dealer_points:
 print("Dealer wins (dealer has more points than the player).")
 else:
 print("It's a tie.")
 break
 else:
 print("Unknown input.")
 continue

Answer 1

cryptic index

deck = [(value, suit) for ... ]
def card_points(card):
 if card[0] in ['Jack', 'Queen', 'King']:
 return 10
 elif card[0] == 'Ace':

The tuples in that first line are very nice and pythonic. But this would have been even nicer:

from collections import namedtuple
Card = namedtuple('Card', 'value suit')
deck = [Card(value, suit) for ... ]

Then later on we could speak of card.value without a cryptic [0] subscript.

enum

Consider defining class Value(Enum):, and moving the card_points() logic into that class. It is reasonable that a Jack object could display one way as a string yet also return 10 as a value.

unicode cards

The way you display cards is perfectly fine. It is worth noting that 52 unicode codepoints offer an alternate means of displaying them.

common logic

player_cards = [deck.pop(), deck.pop()]
dealer_cards = [deck.pop()]
player_points = sum(card_points(card) for card in player_cards)
dealer_points = sum(card_points(card) for card in dealer_cards)

Consider defining class Hand:, and maintaining a list of Hands. Then indexing it gives you either the player or the dealer, and its .points() method gives you its total value.

DRY

Several times you print four items: {player,dealer} {cards,points}. Please extract a helper function.

cite your reference

The code should mention up top what game it implements. From the link in the Review Context I initially thought you meant standard blackjack, but this code implements a variant. I don't see any logic for Ace sometimes being worth 11 and sometimes 1.

Answer 2

Overview

You've done a good job:

• You leveraged code written by others with the import
• Used meaningful names for many of the variables

Here are some adjustments for you to consider, mainly for coding style.

Layout

I recommend moving the functions to the top, after the import. Having them in the middle of the code interrupts the natural flow of the code (from a human readability standpoint).

Unused code

I was about to recommend changing the name of the points function because it seemed too generic. However, I realized that it is not used, so it can be deleted.

Documentation

The card_points function always returns 11 for the Ace. The normal rules of Blackjack allow for the Ace to have a value of 1 in some circumstances.

You should add documentation to describe whether or not the Ace can have a value of 1.

Input

It is great that you cast the user input into lower-case. It would also be helpful to allow the user to be lazy and just input h for "hit" or s for "stand".

DRY

These lines appear 3 times in the code:

 print("Dealer's Cards:", dealer_cards)
 print("Dealer's Points:", dealer_points)
 print("Player's Cards:", player_cards)
 print("Player's Points:", player_points)

You could add them into a new function, named something like show_cards, then call the function 3 times.