🔒 Learning Python and trying to build a Blackjack game as practice, function returning Nonetype | Python | Page 1

zealous lilyBOT Feb 23, 2024, 1:42 AM

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@young cypress

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young cypress Feb 23, 2024, 1:43 AM

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Well rip gotta type it all out again hahaha.

I am currently learning Python at a power rate.

Currently I am practicing by creating a blackjack game and it is SO nearly complete but one small issue is creeping up. One of my functions is returning NoneType but I cannot work out for the life of me why it might be doing it. (Any code critique and recommendations would be appreciated also!)

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https://paste.pythondiscord.com/VPAQ

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Now I BELEIVE the issue lies somehow within the DealerCheck() function as its when it returns it becomes NoneType but not before or during the function as far as I can see.

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I suspect I am perhaps misunderstanding something fundamental about python

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Okay now I am more confused, for the first time Ive had the PLAYER score come back as NoneType sooooo.... Unsure 🥲

cinder verge Feb 23, 2024, 1:51 AM

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In your function DealerCheck, you dont return anything if the dealerscore is <17, but you always expect a return

sly tulip Feb 23, 2024, 1:51 AM

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I don't see baseDeck defined anywhere so its not clear where that is coming from

young cypress Feb 23, 2024, 1:52 AM

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sly tulip I don't see `baseDeck` defined anywhere so its not clear where that is coming fr...

apologies thats outside of this, baseDeck does work fine however its not done elegantly 🙂

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young cypress Feb 23, 2024, 1:52 AM

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cinder verge In your function DealerCheck, you dont return anything if the dealerscore is <17...

Should it not loop and therefore not need a return as I send it back into the same function with the output?

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DealerCheck(dealerScore)

golden geyser Feb 23, 2024, 1:54 AM

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Which function is returning NoneType?

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Paste your code and the traceback please.

cinder verge Feb 23, 2024, 1:55 AM

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young cypress Should it not loop and therefore not need a return as I send it back into the sa...

No idea why i didnt see that, my bad

sly tulip Feb 23, 2024, 1:55 AM

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young cypress Should it not loop and therefore not need a return as I send it back into the sa...

you should look into while loops for your game logic

young cypress Feb 23, 2024, 1:56 AM

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golden geyser Which function is returning NoneType?

It seems to be on both PlayerCheck and DealerCheck on the elif dealerScore >= 17:

young cypress Feb 23, 2024, 1:57 AM

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sly tulip you should look into while loops for your game logic

I was using a while loop, I removed it as I was getting this same error to see if I could fix it in another way but its still returning NoneTypes, once I figure out and understand why this issue is happening Ill return it to a while loop ^^

young cypress Feb 23, 2024, 1:58 AM

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golden geyser Paste your code and the traceback please.

The aim of the game is to make 21 with your cards without going over.
You will go first, and dealer will go second.
The Dealer MUST always choose hit unless they are at 17 or above in which case they MUST stand.
In this version of the game, a Blackjack is an automatic win unless both players get one.
Ace is always 1 unless within a Blackjack (Starting hand of 21)
Are you ready? Y/N: Y
You drew K♦
The Dealer drew
score is checked
You drew 5♦
The Dealer drew
Your cards are: ['K♦', '5♦']
The Dealers first card is: 3♦
score is checked
score is checked
score is checked
score is checked
Your current score is: 15
The Dealers score is: 13
Hit or Stand?: stand
<class 'int'>
Your score is 15
Would you like to Hit or Stand?: stand
You stand on 15
<class 'int'>
The Dealer Draws 10♠
score is checked
The Dealers Score is 23
<class 'int'>
The Dealer is bust at 23
dealerScore final
<class 'NoneType'>
playerScore final
<class 'int'>
Traceback (most recent call last):
  File "d:\webdevprojects\Python Course\CardGames.py", line 260, in <module>
    SelectAGame()
  File "d:\webdevprojects\Python Course\CardGames.py", line 19, in SelectAGame
    BlackJack()
  File "d:\webdevprojects\Python Course\CardGames.py", line 255, in BlackJack
    SelectAGame()
  File "d:\webdevprojects\Python Course\CardGames.py", line 19, in SelectAGame
    BlackJack()
  File "d:\webdevprojects\Python Course\CardGames.py", line 250, in BlackJack
    CheckWin(playerScore, dealerScore)
  File "d:\webdevprojects\Python Course\CardGames.py", line 189, in CheckWin
    elif playerScore <= 21 and dealerScore > 21:
                               ^^^^^^^^^^^^^^^^
TypeError: '>' not supported between instances of 'NoneType' and 'int'```

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the lines on this will be different to the pastebin

golden geyser Feb 23, 2024, 2:03 AM

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score = int(0)

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why?

young cypress Feb 23, 2024, 2:03 AM

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Another attempt at trying to figure out where the datatype issue is coming from

golden geyser Feb 23, 2024, 2:04 AM

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Is dealerScore defined after line 130 in the paste?

young cypress Feb 23, 2024, 2:04 AM

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golden geyser Is dealerScore defined after line 130 in the paste?

Why wouldnt it be? it was used like two lines before

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It wouldnt undefine itself would it?

golden geyser Feb 23, 2024, 2:05 AM

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no but the CheckScore might return NoneType

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let me read the code closer

young cypress Feb 23, 2024, 2:06 AM

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golden geyser ` score = int(0)`

Ill just update this back

sly tulip Feb 23, 2024, 2:13 AM

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Shouldn't the last line of ```py
def DealerCheck(dealerScore):
if dealerScore > 21:
print("The Dealer is bust at "+ str(dealerScore))
return dealerScore
elif dealerScore >= 17:
print("The dealer stands at " + str(dealerScore))
return dealerScore
elif dealerScore < 17:
x = random.choice(baseDeck)
print("The Dealer Draws "+ x)
dealerScore = dealerScore + CheckScore(x)
print("The Dealers Score is " + str(dealerScore))
DealerCheck(dealerScore)

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be py return DealerCheck(dealerScore)

young cypress Feb 23, 2024, 2:14 AM

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Would return be necessary here?

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Since its not returning anything to the original class just running the class again

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with the new value

golden geyser Feb 23, 2024, 2:14 AM

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that's not a class, it's a function

sly tulip Feb 23, 2024, 2:14 AM

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you check the score here dealerScore = DealerCheck(dealerScore)

young cypress Feb 23, 2024, 2:15 AM

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golden geyser that's not a class, it's a function

yeah I mispoke 😛

sly tulip Feb 23, 2024, 2:15 AM

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and the result is less than 17 so it goes to the last statement and calls itself

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and then returns when its a bust to itself but the main calling function never gets a return

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Try it and see

young cypress Feb 23, 2024, 2:16 AM

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Shouldnt it only return when the conditoons are satisfied?

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and if that section is running then the conditions arent met

sly tulip Feb 23, 2024, 2:18 AM

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!e ```py

def foo(x):
if x > 5:
return True
else:
x+=1
foo(x)

y = foo(1)
print(y)```

zealous lilyBOT Feb 23, 2024, 2:18 AM

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@sly tulip :white_check_mark: Your 3.12 eval job has completed with return code 0.

None

sly tulip Feb 23, 2024, 2:18 AM

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see ^

young cypress Feb 23, 2024, 2:19 AM

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Interesting

sly tulip Feb 23, 2024, 2:19 AM

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!e ```py

def foo(x):
if x > 5:
return True
else:
x+=1
return foo(x)

y = foo(1)
print(y)```

zealous lilyBOT Feb 23, 2024, 2:19 AM

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@sly tulip :white_check_mark: Your 3.12 eval job has completed with return code 0.

True

young cypress Feb 23, 2024, 2:19 AM

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Im not getting any errors now

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I dont understand "why" a return should be needed in that scenario since the function hasn't passed back to the call yet

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Wel its awesome that its working, But i definately do not like that I dont understand why xD if you have any way to explain it I would apprecaite it

sly tulip Feb 23, 2024, 2:21 AM

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Let me see if I can find a resource that can explain better

young cypress Feb 23, 2024, 2:21 AM

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Thanks, I apprecaite it

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Oof time to dive back in

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My score should NOT be 2 xD

sly tulip Feb 23, 2024, 2:23 AM

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This would probably be helpful https://realpython.com/python-recursion/. My understanding of it is essentially it creats a namespace when you call your function. When it goes through the conditions and recursively calls itself it creates another namespace where the value is returned to that original call. But since theres no return statement your first call just gets None back.

Recursion in Python: An Introduction – Real Python

In this tutorial, you'll learn about recursion in Python. You'll see what recursion is, how it works in Python, and under what circumstances you should use it. You'll finish by exploring several examples of problems that can be solved both recursively and non-recursively.

young cypress Feb 23, 2024, 2:23 AM

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young cypress

nvm I worked it out

young cypress Feb 23, 2024, 2:23 AM

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sly tulip This would probably be helpful https://realpython.com/python-recursion/. My unde...

Interesting

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Ill take a look thank you.

sly tulip Feb 23, 2024, 2:25 AM

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another good one https://www.programiz.com/python-programming/recursion

Python Recursion (Recursive Function)

In this tutorial, you will learn to create a recursive function (a function that calls itself).

young cypress Feb 23, 2024, 2:25 AM

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Thanks 🙂

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Alrighty Now to deal with Ace 1/11 =_=

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(currently it only scores 1)

sly tulip Feb 23, 2024, 2:27 AM

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you should make an enum class for your base deck

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Then you can set your cards Display str with its corresponding value

sly tulip Feb 23, 2024, 2:28 AM

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young cypress Alrighty Now to deal with Ace 1/11 =_=

Yeah this would require some added effort

young cypress Feb 23, 2024, 2:29 AM

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sly tulip Then you can set your cards Display str with its corresponding value

Wouldnt a dictionary work for this?

sly tulip Feb 23, 2024, 2:29 AM

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Its basically the same thing

young cypress Feb 23, 2024, 2:29 AM

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Ive never done an enum class, something to look into

sly tulip Feb 23, 2024, 2:29 AM

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personally I think enums are more structured and easier to read and use

young cypress Feb 23, 2024, 2:30 AM

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Im gonna head off now, but Ill add it to my notes and check it out tomorrow. Thank you!

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I think Ive made some good progress with learning Python in what 2/3 days so far x3

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Definately helps that i have knowledge of c#/++ etc but honestly I think I already know more about python than those kek

zealous lilyBOT Feb 23, 2024, 3:31 AM

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Python help channel closed

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#🔒 Learning Python and trying to build a Blackjack game as practice, function returning Nonetype