我收到警告：“名称‘x’可以未定义”和“全局变量‘x’在模块级别未定义”

Question

我一直在处理我的代码，并且弹出了一些警告，如“名称'x'可以未定义”和“全局变量'x'在模块级别未定义”

快速了解程序的功能： 它可以登录用户 如果没有这个名字的用户，它可以叹息一个用户可以提取或存款到他的帐户

任何人都可以快速通过我的代码 go 告诉我问题是什么吗？ 如果有任何明显的错误，请告诉我。 将不胜感激。

users_info = {
    'Bill_Cruz': {
        'age': 45,
        'number': '+248-4052-388',
        'card': '5269-5440-9962-2708',
        'balance': 4321.54,
        'password': 'bill'
    },
    'Robert_Soup': {
        'age': 34,
        'number': '+562-5065-778',
        'card': '4716-7816-7850-1836',
        'balance': 12701,
        'password': 'robertsoup123'
    },
    'Paula_Smith': {
        'age': 41,
        'number': '+231-7307-367',
        'card': '4556-4566-2049-4595',
        'balance': 75.65,
        'password': 'paulasmith123'
    }
}


def name_validation():
    global name, name_edited **### line 27**
    while True:
        name = input('Please give me your name and surname: ').title().strip()
        name_edited = name.replace(" ", "_")
        if name.lower().strip() == "r":
            print('Wellcome to the registration page!')
            new_name = input('I`m gonna need your name and surname: ').title().strip()
            new_name_edited = new_name.strip().replace(" ", "_")
            users_info.update({new_name_edited: {'password': input('Enter a new password: ').strip(),
                                                 'balance': 0}})
            name = new_name
            name_edited = new_name_edited
            break
        elif name_edited not in users_info.keys():
            print('USER NOT FOUND, try again: (r - for signing up)')
            continue
        else:
            break


def log_in():
    attempts = 3
    while True:
        if attempts != 0:
            password = input(f'Please enter your password\n(attempts left - {attempts}): ').strip()
            if password == users_info[name_edited]['password']:
                print('>>>>>>>>>>>>>>><<<<<<<<<<<<<<<')
                print('You`ve successfully logged in!')
                break
            else:
                print('The password you`ve entered is incorrect')
                attempts -= 1
                continue
        else:
            print('You have 0 attempts left \nBye')
            quit()
        break


def balance_interaction():
    new_balance = None
    while True:
        print('Would you like to interact?')
        user_action = input('("d" for deposit; "w" for withdrawal; "q" to quit): ')
        if user_action == "d":
            while True:
                try:
                    while True:  # checking if dep ammount is valid
                        deposit = float(input('How much money would you like to deposit?: '))
                        if deposit >= 0:
                            new_balance = users_info[name_edited]['balance'] + deposit
                            break
                        else:
                            print('Cannot ne negative!')
                            continue
                    break
                except ValueError:
                    print()
                    print('Enter an amount of money you`d like to deposit!')
                    continue
            break
        elif user_action == "w":
            while True:
                try:
                    while True:
                        withdraw = float(input('How much money would you like to withdraw?: '))
                        if withdraw >= 0:
                            if users_info[name_edited]['balance'] - withdraw >= 0:
                                new_balance = users_info[name_edited]['balance'] - withdraw
                                break
                            else:
                                print(f'Not enough money on the account. '
                                      f'Your available balance is {users_info[name_edited]["balance"]}')
                                continue
                        else:
                            print('Cannot ne negative!')
                            continue
                    break
                except ValueError:
                    print()
                    print('Enter an amount of money you`d like to withdraw!')
                    continue
            break
        elif user_action == "q":
            print('Bye!')
            quit()
        else:
            print('Enter something valid!')
            continue
    print(f'Your new available balance is $ {round(new_balance, 2)}')


name_validation()
print(f'Hello, {name}') **### line 120**
log_in()
balance = users_info[name_edited]['balance'] **### line 122**
print(f'Your balance is $ {round(balance, 2)}')
balance_interaction()

有报错截图

显然问题出在变量的全球化中，但我无法弄清楚到底是什么。

Answer 1

作为一名程序员，您应该非常、非常、非常努力地尝试不使用全局变量。

在这种情况下并不困难。 只需根据需要将name和name_edited传入和传出函数。

users_info = {
    'Bill_Cruz': {
        'age': 45,
        'number': '+248-4052-388',
        'card': '5269-5440-9962-2708',
        'balance': 4321.54,
        'password': 'bill'
    },
    'Robert_Soup': {
        'age': 34,
        'number': '+562-5065-778',
        'card': '4716-7816-7850-1836',
        'balance': 12701,
        'password': 'robertsoup123'
    },
    'Paula_Smith': {
        'age': 41,
        'number': '+231-7307-367',
        'card': '4556-4566-2049-4595',
        'balance': 75.65,
        'password': 'paulasmith123'
    }
}


def name_validation():
    while True:
        name = input('Please give me your name and surname: ').title().strip()
        name_edited = name.replace(" ", "_")
        if name.lower().strip() == "r":
            print('Wellcome to the registration page!')
            new_name = input('I`m gonna need your name and surname: ').title().strip()
            new_name_edited = new_name.strip().replace(" ", "_")
            users_info.update({new_name_edited: {'password': input('Enter a new password: ').strip(),
                                                 'balance': 0}})
            name = new_name
            name_edited = new_name_edited
        elif name_edited not in users_info.keys():
            print('USER NOT FOUND, try again: (r - for signing up)')
            continue
        return name, name_edited


def log_in(name_edited):
    attempts = 3
    while True:
        if attempts != 0:
            password = input(f'Please enter your password\n(attempts left - {attempts}): ').strip()
            if password == users_info[name_edited]['password']:
                print('>>>>>>>>>>>>>>><<<<<<<<<<<<<<<')
                print('You`ve successfully logged in!')
                break
            else:
                print('The password you`ve entered is incorrect')
                attempts -= 1
                continue
        else:
            print('You have 0 attempts left \nBye')
            quit()
        break


def balance_interaction(name_edited):
    new_balance = None
    while True:
        print('Would you like to interact?')
        user_action = input('("d" for deposit; "w" for withdrawal; "q" to quit): ')
        if user_action == "d":
            while True:
                try:
                    while True:  # checking if dep ammount is valid
                        deposit = float(input('How much money would you like to deposit?: '))
                        if deposit >= 0:
                            new_balance = users_info[name_edited]['balance'] + deposit
                            break
                        else:
                            print('Cannot ne negative!')
                            continue
                    break
                except ValueError:
                    print()
                    print('Enter an amount of money you`d like to deposit!')
                    continue
            break
        elif user_action == "w":
            while True:
                try:
                    while True:
                        withdraw = float(input('How much money would you like to withdraw?: '))
                        if withdraw >= 0:
                            if users_info[name_edited]['balance'] - withdraw >= 0:
                                new_balance = users_info[name_edited]['balance'] - withdraw
                                break
                            else:
                                print(f'Not enough money on the account. '
                                      f'Your available balance is {users_info[name_edited]["balance"]}')
                                continue
                        else:
                            print('Cannot ne negative!')
                            continue
                    break
                except ValueError:
                    print()
                    print('Enter an amount of money you`d like to withdraw!')
                    continue
            break
        elif user_action == "q":
            print('Bye!')
            quit()
        else:
            print('Enter something valid!')
            continue
    print(f'Your new available balance is $ {round(new_balance, 2)}')


name, name_edited = name_validation()
print(f'Hello, {name}')
log_in(name_edited)
balance = users_info[name_edited]['balance']
print(f'Your balance is $ {round(balance, 2)}')
balance_interaction(name_edited)

Answer 2

这些消息警告您全局变量name和name_edited只能通过运行name_validation() function 来定义。如果您没有运行 function，这些变量将不存在。

在模块的顶部定义这些变量是更安全的做法，因此它们肯定存在于全局 scope 中，而不依赖于运行 function。