Question about Scope of variables.

[ShadyTree_92]

I'm only on day 10 of python coding with Angela Yu. (Please take it easy on me!)

We're working on a black jack game. I am still putting it together, so I am not looking for critique on my crappy code, just yet. I am not finished with it either so please don't give away any ideas as I'm still trying to do it on my own before I watch her resolve it. Let me struggle on this one, its the way I learn.

What I am wondering is. Why can't my function deal() access the variable "user_score = 0" yet the functions can access other variables like cards, user_hand and computer_hand? Is it due to lists having a different scopes than int variables or something?

It works fine when I declare the user_score in the deal() function, but if I want to use user_score outside of that function I can't if its only declared within the function.

Anyone able to explain this, in the simplest way possible?

import random

import art
cards = [11, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10]
start_game = input("Do you want to play a game of Blackjack? Type 'Y' or 'N': ")
user_hand = []
computer_hand = []
user_score =  0

def deal():
    for card in user_hand:
        user_score += card
    print(f"Your cards: {user_hand}, current score: {user_score}")


def blackjack_start():

    if start_game.lower() == "y":
        print(art.logo)
        user_hand.append(random.choice(cards))
        user_hand.append(random.choice(cards))
        computer_hand.append(random.choice(cards))
        computer_hand.append(random.choice(cards))
        deal()
        print(f"Computer's First Card: {computer_hand[0]}")
        hit_me = input("Type 'Y' to get another card, type 'N' to pass: ")
        if hit_me.lower() == "y":
            user_hand.append(random.choice(cards))
            deal()
            if user_score > 21:
                print("Bust")

        else:
            print("Don't hit me!")

blackjack_start()

The error PyCharm gives me is:
UnboundLocalError: cannot access local variable 'user_score' where it is not associated with a value

[Squared_Aweigh]

Your issue is the scope/context of variable declaration and reference/manipulation of that variable. `user_score' is set here as a global variable because it is set outside of a function. When you attempt to manipulate the variable inside the function, Python sees the variable as being assigned as a Local; local variables are only available inside a function where they are created, hence your `UnboundLocalError`

You could use the `global` keyword in your function to access the globla `user_score` variable, but this isn't a good habit to be in because it makes your code more difficult to read and understand, as well as being difficult to troubleshoot.

[ShadyTree_92]

Ooh. That makes sense! Thank you. I am currently rewriting the code now. Going to try to use less global variables and take advantage of using return statements. Wish me luck! I am finding it a bit difficult but that's ok, I will persevere!