Exercise – Coding a Banking Program

Back to: Python Programming

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This is an exercise do help us practice using functions in Python. We’ll start by breaking the program into smaller sections and work on them one at a time.

We’ll define three functions:  show_balance(), deposit() and withdraw(). Read through this code and ensure you fully understand what each function does and how it is working. Notice that there is a great deal of validity testing.

# Python Banking Program

def show_balance(balance):
    print("*********************")
    print(f"Your balance is ${balance:.2f}")
    print("*********************")

def deposit():
    print("*********************")
    amount = float(input("Enter an amount to be deposited: "))
    print("*********************")
    if amount < 0:
        print("*********************")
        print("That's not a valid amount")
        print("*********************")
        return 0
    else:
        return amount

def withdraw(balance):
    print("*********************")
    amount = float(input("Enter amount to be withdrawn: "))
    print("*********************")

    if amount > balance:
        print("*********************")
        print("Insufficient funds")
        print("*********************")
        return 0
    elif amount < 0:
        print("*********************")
        print("Amount must be greater than 0")
        print("*********************")
        return 0
    else:
        return amount

def main():
    balance = 0
    is_running = True

    while is_running:
        print("*********************")
        print("   Banking Program   ")
        print("*********************")
        print("1.Show Balance")
        print("2.Deposit")
        print("3.Withdraw")
        print("4.Exit")
        print("*********************")
        choice = input("Enter your choice (1-4): ")

        if choice == '1':
            show_balance(balance)
        elif choice == '2':
            balance += deposit()
        elif choice == '3':
            balance -= withdraw(balance)
        elif choice == '4':
            is_running = False
        else:
            print("*********************")
            print("That is not a valid choice")
            print("*********************")

    print("*********************")
    print("Thank you! Have a nice day!")
    print("*********************")

if __name__ == '__main__':
    main()

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