函数&返回到以前的代码python

Question

import random
import math

main_menu = [
    "1 - Display Balance",
    "2 - Withdraw Funds",
    "3 - Deposit Funds",
    "9 - Return Card",
]
print("Welcome to Northern Frock")
print(main_menu[0])
print(main_menu[1])
print(main_menu[2])
print(main_menu[3])

atm_input_1 = int(
    input(
        "Select 1 to display the current balance and the maximum amount available for withdrawal (In £10 increments) \n select 2 to view avalaible withdrawal amounts \n Select 3 to deposit funds \n select 9 to return card!"
    )
)
current_balance = random.randint(10, 1000)
withdrawal_balance = math.floor(current_balance / 10) * 10

if atm_input_1 == 1:

    print("Current Balance:", "£", current_balance)

    print("Withdrawal Balance:", "£", withdrawal_balance)

elif atm_input_1 == 2:
    sub_menu = [
        "1 - £10",
        "2 - £20",
        "3 - £40",
        "4 - £60",
        "5 - £80",
        "6 - £100",
        "7 - Other amount",
        "8 - Return to main menu",
    ]
    print("Please select withdrawal amount")
    print(sub_menu[0])
    print(sub_menu[1])
    print(sub_menu[2])
    print(sub_menu[3])
    print(sub_menu[4])
    print(sub_menu[5])
    print(sub_menu[6])
    print(sub_menu[7])

    sub_menu_input = int(input("Please select a number from the options below"))
    if sub_menu_input == 1:
        if withdrawal_balance >= 10:
            print("£10 successfully withdrawed from account")
            current_balance - 10
            withdrawal_balance - 10
            print("Current Balance:", "£", current_balance)
            print("Withdrawal Balance:", "£", withdrawal_balance)

        else:
            print("Sorry you currrently have insufficent funds for a withdrawal")
    elif sub_menu_input == 2:
        if withdrawal_balance >= 10:
            print("£20 successfully withdrawed from account")
            current_balance - 20
            withdrawal_balance - 20
            print("Current Balance:", "£", current_balance)
            print("Withdrawal Balance:", "£", withdrawal_balance)

        else:
            print("Sorry you currrently have insufficent funds for a withdrawal")

    elif sub_menu_input == 3:
        if withdrawal_balance >= 10:
            print("£40 successfully withdrawed from account")
            current_balance - 40
            withdrawal_balance - 40
            print("Current Balance:", "£", current_balance)
            print("Withdrawal Balance:", "£", withdrawal_balance)

        else:
            print("Sorry you currrently have insufficent funds for a withdrawal")

    elif sub_menu_input == 4:
        if withdrawal_balance >= 10:
            print("£60 successfully withdrawed from account")
            current_balance - 60
            withdrawal_balance - 60
            print("Current Balance:", "£", current_balance)
            print("Withdrawal Balance:", "£", withdrawal_balance)

        else:
            print("Sorry you currrently have insufficent funds for a withdrawal")

    elif sub_menu_input == 5:
        if withdrawal_balance >= 10:
            print("£80 successfully withdrawed from account")
            current_balance - 80
            withdrawal_balance - 80
            print("Current Balance:", "£", current_balance)
            print("Withdrawal Balance:", "£", withdrawal_balance)

        else:
            print("Sorry you currrently have insufficent funds for a withdrawal")

    elif sub_menu_input == 6:
        if withdrawal_balance >= 10:
            print("£100 successfully withdrawed from account")
            current_balance - 100
            withdrawal_balance - 100
            print("Current Balance:", "£", current_balance)
            print("Withdrawal Balance:", "£", withdrawal_balance)

        else:
            print("Sorry you currrently have insufficent funds for a withdrawal")

    elif sub_menu_input == 7:
        withdrawal_request = int(
            input("Please enter amount you wish to withdraw (In a £10 sequence")
        )
        if withdrawal_request % 10 == 0:
            if withdrawal_balance >= withdrawal_request:
                print("£", withdrawal_balance, "successfully withdrawed from account")
                current_balance - withdrawal_request
                withdrawal_balance - withdrawal_request
                print("Current Balance:", "£", current_balance)
                print("Withdrawal Balance:", "£", withdrawal_balance)

        else:
            print("ERROR Invalid withdrawal request")

elif atm_input_1 == 3:
    deposit_request = int(
        input("Please enter the amount you wish to deposit into your account")
    )
    current_balance = current_balance + deposit_request
    withdrawal_balance = math.floor((withdrawal_balance + deposit_request) / 10) * 10
    print("you have successfully deposited £", deposit_request, "into your account")
    print("updated balances:")
    print("Current Balance:", "£", current_balance)
    print("Withdrawal Balance:", "£", withdrawal_balance)

elif atm_input_1 == 9:
    print("Card returned , thank you for banking with Northern Frock good day")
    quit()

else:
    print("Error invalid selection try again")

2问题如何在退出、保存和显示余额2之后返回主菜单(第一个用户输入)如何将程序编写为函数或一系列函数，而不是当前的形式--在我的开发过程中，任何帮助都将受到极大的赞赏，谢谢:)目前，用户受到第一个主菜单的欢迎(我需要用户在每次结束后也返回>，而不是在程序结束后停止工作，就像我不得不选择离开

的>实际atm一样)。

Answer 1

首先，要让程序运行到完成，我们需要在一个循环中运行。

def main():
    print("Welcome to Northern Frock")
    account = {'balance': random.randint(10, 1000)}
    while not _main_menu(account):
        pass

其次，您可以定义每个函数都执行一些任务，并从这些函数逐个构建程序。

选择菜单选项。此函数显示该选项并返回用户选择。

def _get_input(options: list, keys=None):
    if keys is None:
        keys = list(range(1, len(options) + 1))

    msg = '\n'.join(f'{i} - {m}' for i, m in zip(keys, options))
    try:
        opt = int(input(msg))
        if opt in keys:
            return opt
        else:
            return -1
    except ValueError:
        print(f'Please select an option from the list')
        return -1

自定义输入量。简单的功能，得到一个数字的定制存款和取款。

def _custom_amount():
    try:
        amount = int(input('Please enter amount: '))
        if amount < 0:
            print('ERROR Please enter a number greater than 0')
            return 0
        else:
            return amount
    except ValueError:
        print('ERROR Please enter a number')
        return 0

主菜单功能，在帐户上工作。

def _display_balance(account):
    print(f"Current Balance: £{account['balance']}")
    print(f"Withdrawal Balance: £{int(account['balance'] / 10) * 10}")

def _withdraw_funds(account):
    amounts = {1: 10, 2: 20, 3: 40, 4: 60, 5: 80, 6: 100, 7: _custom_amount}
    options = [
        "£10",
        "£20",
        "£40",
        "£60",
        "£80",
        "£100",
        "Other amount",
        "Return to main menu"
    ]

    selection = _get_input(options)
    while selection == -1:
        selection = _get_input(options)
    if selection in amounts:
        if selection < 7:
            amount = amounts[selection]
        else:
            amount = amounts[selection]()
        if not amount:
            return False
        available = int(account['balance'] / 10) * 10
        if amount % 10 or amount > available:
            print("ERROR Invalid withdrawal request")
        else:
            account['balance'] -= amount
            print(f"£{amount} successfully withdrawn from account")
            _display_balance(account)
    return False

def _deposit_funds(account):
    amounts = {1: 10, 2: 20, 3: 40, 4: 60, 5: 80, 6: 100, 7: _custom_amount}
    options = [
        "£10",
        "£20",
        "£40",
        "£60",
        "£80",
        "£100",
        "Other amount",
        "Return to main menu"
    ]

    selection = _get_input(options)
    while selection == -1:
        selection = _get_input(options)
    if selection in amounts:
        if selection < 7:
            amount = amounts[selection]
        else:
            amount = amounts[selection]()
        if not amount:
            return False
        account['balance'] += amount
        print(f"You have successfully deposited £{amount} into your account")
        _display_balance(account)
    return False

def _return_card(account):
    print("Card returned , thank you for banking with Northern Frock good day")
    return True

以及主菜单功能本身。

def _main_menu(account):
    callees = {1: _display_balance, 2: _withdraw_funds, 3: _deposit_funds, 9: _return_card}
    keys = [1, 2, 3, 9]
    options = [
        "Display Balance",
        "Withdraw Funds",
        "Deposit Funds",
        "Return Card"
    ]
    selection = _get_input(options, keys)
    while selection == -1:
        selection = _get_input(options, keys)
    return callees[selection](account)