Python version of 1973 BLAKJAK (101 Basic Computer Games)

## Blakjak - rewritten from "BLAKJAK" in 101 Basic Computer Games

# This game was originally published in the seminal anthology '101 Computer Games
# in Basic' in 1973. The original source code is a Gordian knot of jumbled
# spaghetti code which proved to be mostly unsalvagable so that I chose to use the
# basic game algorithm but preferred to completely rewrite the game from scratch,
# following the sample game in the book. (May 2020, Nele Abels)
# (Creative commons license: CC BY-SA)

import random
import sys

# carddeck[] represents a deck of playing cards: Two to ten, Jack, Queen, King, Ace.
# The deck is used for counting which cards have been drawn by pick_a_card() and
# may contain the numbers 0 to 4. (e.g. all the four aces have been drawn or no 2)

cardnames = ["two","three","four","five","six","seven","eight","nine","ten",
             "Jack","Queen","King","Ace"]
carddeck = [0,0,0,0,0,0,0,0,0,0,0,0,0]

# money - the player starts with this hefty sum of hard earned dollars

money = 500

# ask_yes_or_no() - get Userinput, only "y" and "n" accepted,return 0 or 1

def ask_yes_or_no():
    ein="."
    while "yn".find(ein)<0:
        ein=input("(y/n) ").lower()
    if ein=="y":
        return 1
    else:
        return 0

# pick_a_card() - draws a random card from the pack, checks before if all colours
# of the card have been drawn, prints the card, returns its value.
# The global values list counts the number of a specific type of cards (e.g. Queens).
# The routine does not differentiate between colours.

def pick_a_card():
    global carddeck
    card_ok = 0
    while not card_ok:
        pick = random.randint(0,12)
        if carddeck[pick] < 4:
            card_ok = 1
    print(cardnames[pick],end="")
    carddeck[pick] = carddeck[pick] + 1
    if pick < 9:
        value = pick + 2            # numbers
    elif pick == 12:
        value = 11                  # Ace
    else:
        value = 10                  # Jack, Queen, King
    return value

# enter_wager() - inputs wager from the keyboard, checks type and sum

def enter_wager():
    fertig = 0
    while fertig == 0:
        correctinput = 0
        while correctinput == 0:
            print("How much money to you want to bet? ",end="")
            try:
                ein = int(input())
                correctinput = 1
            except:
                print("Please enter a positive, rounded value (e.g. 200).")
        if ein<1:
            print("Please...")
        elif ein>money:
            print("Sorry, the bank does not give credit.")
        else:
            fertig = 1
    return ein

# game_round() - play one round of blackjack until player or dealer are busted
# or one of them wins the game. Return endresult: 0 - dealer has won, 1 - player has won

def game_round(playerpoints, dealerpoints):
    round_over = 0
    player_stopped_hitting = 0
    endresult = 0

    while round_over == 0:
        print("You have {} showing.".format(playerpoints))
        print("The dealer has {} showing.".format(dealerpoints))

        # check if player or dealer have already a 21

        if playerpoints == 21:
            print("You have a blackjack!")
            round_over=1
            endresult = 1
        elif dealerpoints == 21:
            print("The dealer has a blackjack!")
            round_over = 1
            endresult = 0
        else:

            # If the player has chosen to stop, the routine does not ask again

            if round_over == 0 and player_stopped_hitting == 0:
                print("Do you want a hit? ",end="")
                if ask_yes_or_no() == 1:
                    player_stopped_hitting = 0
                else:
                    player_stopped_hitting = 1
                if player_stopped_hitting == 0:
                    print("You draw a card: ",end="")
                    playerpoints = playerpoints + pick_a_card()
                    print("\n")
                    if playerpoints > 21:
                        print("You busted!")
                        round_over = 1
                        endresult = 0
                    elif playerpoints == 21:
                        print("Blackjack!")
                        round_over = 1
                        endresult = 1

            # The dealer only hits if he has under 17 points and the game is not over, yet


            if round_over == 0 and (dealerpoints<17 or playerpoints>dealerpoints):
                print("The dealer draws a card: ",end="")
                dealerpoints = dealerpoints + pick_a_card()
                print("\n")
                if dealerpoints > 21:
                    print("The dealer busted!")
                    round_over = 1
                    endresult = 1
                elif dealerpoints == 21:
                    print("Blackjack!")
                    round_over = 1
                    endresult = 0

            # Both players have stopped hitting - compare results

            if round_over == 0 and dealerpoints > 16 and player_stopped_hitting == 1:
                if playerpoints > dealerpoints:
                    print("You have won.")
                    round_over = 1
                    endresult = 1
                elif playerpoints < dealerpoints:
                    print("The dealer has won.")
                    round_over = 1
                    endresult = 0
                else:
                    print("It's a draw. Tough luck, the bank gets the money.")
                    round_over = 1
                    endresult = 0
    return endresult

# main routine

print("\n\nWelcome to BLJACK EDUSYSTEM 30 - 2020 Python edition!\n")
print("Welcome to Digital Edusystem Computer Blackjack.\n")
print("Your dealer tonight is Petey P. Eight")
print("Watch him closely... he has a reputation for dealing")
print("off the bottom of his deck.\n")
print("Questions requiring a yes or no answer must be answered with")
print("'y' for yes and 'n' for no.\n")
print("You start playing with {}$. Use it carefully!".format(money))


another_game = 1
while another_game:

    print("\nThe dealer shuffles a new deck.\n")
    for x in range(0,13):
        carddeck[x] = 0

    # How much money does the player want to invest?

    print("You have got {}$ in your wallet.".format(money))
    wager = enter_wager()
    print("You are betting {}$\n".format(wager))

    # Player draws first two cards

    player_points = 0
    print("You draw a ",end="")
    player_points = player_points + pick_a_card()
    print(" and then you draw a ",end="")
    player_points = player_points + pick_a_card()
    print(".")

    # Dealer draws first two cards

    dealer_points = 0
    print("The dealer draws a ",end="")
    dealer_points = dealer_points + pick_a_card()
    print(" and then he draws a ",end="")
    dealer_points = dealer_points + pick_a_card()
    print(".")

    # Play the round till the bitter end

    if game_round(player_points, dealer_points) == 1:
        money = money + wager
        print("\nYay, you have won. Now you own {}".format(money))
    else:
        money = money - wager
        print("\nYou have lost your money...")
    print("Now you own {}".format(money))

    # Another round?

    print("Would you like to play another round? ",end="")
    another_game = ask_yes_or_no()

print("\nThanks for playing, goodbye!")