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POHow do I create something that I can use to access class instances later in my programming?
 

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  1. POHow do I create something that I can use to access class instances later in my programming?
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    <p>I'm a beginning programmer in high school who is interested in computer science. I've been teaching myself to program with Python using Mike Dawson's book, <em>Learning to program for the absolute beginner with Python, 3rd Edition</em>. I'm writing a program to practice my newly acquired knowledge of OOP. The program simulates a bank in which a player can open bank accounts, withdraw/deposit cash, get exchange rates, transfer money from one account to another, and other features. I am having severe trouble with the program, as the main part of the program that simulates the fact that there are multiple accessible accounts that a user can access. I'm now sure how or if it is the way I should be doing things, but I tried writing a class attribute that is an empty list called all_accounts. Each time an account is instantiated, the instance is appended to the list. When a player chooses a menu option such as withdrawing/depositing cash, I want the instance in the list to be accessed so that the object's attributes (such as balance) can be modified. I have no idea how to do this and I've been searching for an answer for about 3 days now without finding anything. Keep in mind, I'm a beginner programmer, so my code will probably be considered poorly written. I'll post the entire code below, as I feel it is necessary that people get a complete feel of how the code works and functions. Also, feel free to notify me of anything else in my code that isn't right or that I could be doing better. I'm always open to learning.</p> <pre><code>class Account(object): """An interactive bank account""" wallet = 0 all_accounts = [] # initial def __init__(self, ID, bal): self.ID = ID self.bal = bal print("A new account has been opened!") Account.all_accounts.append(self) def withdraw(self, w_input): if w_input &lt; self.bal or w_input == 0: print("That is not a valid amount. Sending you back to menu.\n") Menu() else: self.bal = self.bal - w_input print("You withdrew $" + str(w_input) + ".\n") wallet += w_input print("You wallet now contains $" + Account.wallet) Menu() def deposit(self): # Whatever def Menu(): print( """ 0 - Leave the Virtual Bank 1 - Open a new account 2 - Withdraw money 3 - Deposit money 4 - Transfer money from one account to another 5 - Get exchange rates(Euro, Franc, Pounds, Yuan, Yen) """ ) # Add more if necessary choice = input("What would you like to do?: ") while choice != "0": if choice == "1": account_name = input("What is your account's ID?: ") account_bal = float(input("How much money would you like to put into the account?(USD): ")) account_name = Account(ID = account_name, bal = account_bal) Menu() elif choice == "2": account_choice = input("What is your account ID?: ") if account_choice in instance.Account.all_account: withdraw_choice = input("How much money would you like to withdraw?: ") account_choice.withdraw(w_input = withdraw_choice) else: print("Nope.") if choice == "0": print("\nThank you for visiting the virtual bank!") input("Press the [ENTER] key to exit the program.") Menu() </code></pre>
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