CODEWITHSUNDEEP
pythonfunctionwhile-looptype-conversion
qavumm
qavumm

Reputation: 1

Function returning None even though it's terminated by return command Python

I'm trying to write a simple BlackJack program that works on random module, so it picks between the list of cards, and if the picked number belongs to the last 3 variables which are equal to 10, then it goes into an if statement where it decides if the card should king,queen or jack. At the end of if statements I have return statements which should make sure that the function's value when called upon should be the tuples, but when I try to call inside a while statement, I get " line 43, in card_name_x, card_name_y = card_conversion(x,y) ^^^^^^^^^^^^^^^^^^^^^^^^ TypeError: cannot unpack non-iterable NoneType object" because I think function returns None so it can't assign a value to the tuples.

import random

running = True

cards = [11, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10]
blackjack = ["jack", "king", "queen"]

x = cards[random.randint(0,12)]
y = cards[random.randint(0,12)]

player_deck = []
dealer_deck = []

def card_conversion(x,y):
    if x == 10 and y == 10:
        card_name_x = blackjack[random.randint(0, 2)]
        print(card_name_x)
        card_name_y = blackjack[random.randint(0, 2)]
        print(card_name_y)
        return card_name_x, card_name_y
    elif x != 10 and y == 10:
        card_name_y = blackjack[random.randint(0, 2)]
        card_name_x = x
        print(card_name_y)
        return card_name_x, card_name_y
    elif x == 10 and y != 10:
        card_name_x = blackjack[random.randint(0, 2)]
        card_name_y = y
        print(card_name_x)
        return card_name_x, card_name_y

def card_point_total():
    sum = x + y
    return sum

player_turn = True
dealer_turn = True

while running:

    if dealer_turn == True:
        card_conversion(x,y)
        card_name_x, card_name_y = card_conversion(x,y)
        card_point_total()
        dealer_deck.append(card_name_x)
        dealer_deck.append(card_name_y)
        print(card_point_total())
        print(dealer_deck)
        dealer_turn = False
        #player_turn = True

    if player_turn == True:
        card_conversion(x,y)
        card_name_x, card_name_y = card_conversion(x,y)
        player_deck.append(card_name_x)
        player_deck.append(card_name_y)
        print(card_point_total())
        print(player_deck)
        player_turn = False
        #dealer_turn= True

Upvotes: -4

Views: 53

Answers (1)

ti7
ti7

Reputation: 18866

You function doesn't define an else: clause for the if statements, so if none of the conditions are True (namely, when neither x nor y equals 10), your function card_conversion will end and return None as a default

Either expressly return something valid at the end or raise to trap this exceptional case!

>>> def test(a):
...     if a == 1:
...         return 1
...     elif a == 2:
...         return 2
...     raise RuntimeError(f"bug: unexpected value for a: {a}")
... 
>>> test(1)
1
>>> test(2)
2
>>> test(3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 6, in test
RuntimeError: bug: unexpected value for a: 3

Upvotes: 3

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