Python ATM代码报错：'break' outside of loop 问题求助

错误原因 #

• 第一个循环条件逻辑错误：while attempts > 3 初始时attempts=3，条件永远不成立，导致PIN验证流程完全跳过。应改为while attempts > 0，保证有3次输入PIN的机会。
• 第二个循环缩进错误：choose = int(input(...)) 及后续的功能判断代码没有缩进在while True:循环内部，导致elif choose ==4中的break语句不在任何循环结构里，触发'break' outside of loop语法错误。

修正后的完整代码 #

import random

balance = random.randint(100, 1000)
attempts = 3

print('**Welcome To My ATM**')

# 修正循环条件：从attempts>3改为attempts>0
while attempts > 0:
    pin = input('Please enter your 4-digit PIN: ')
    if pin == '0000':
        print('CORRECT PIN')
        break
    else:
        attempts -= 1
        print(f'INCORRECT PIN. You have {attempts} attempt/s left, try again.')

if attempts == 0:
    print('You have exceeded your attempts limit.')
    print('Please take your card')
else:
    while True:
        print('1: Check Balance')
        print('2: Deposit')
        print('3: Withdraw')
        print('4: Exit')
        # 以下代码全部缩进，纳入while True循环内部
        choose = int(input('Choose which service you want from 1 to 4: '))
        if choose == 1:
            print('Your current balance is', balance)
        elif choose == 2:
            amount1 = int(input('Please enter the amount you want to deposit: '))
            balance += amount1
            print('Your new balance will be displayed in a moment...')
            print(balance)
        elif choose == 3:
            amount2 = int(input('Please enter the amount you want to withdraw: '))
            if balance >= amount2:
                balance -= amount2
                print('Cash will be out any moment...')
                print('Your new balance is ', balance)
            else:
                print('Sorry, insufficient funds. Current balance is ', balance)
        elif choose == 4:
            print('Thank you for using this ATM.')
            break
        else:
            print('Invalid choice, please try again')

额外优化说明 #

• 修正了原代码中Pleas的拼写错误，改为Please
• 修正了Cash is will be out的语法错误，改为Cash will be out
• 使用f-string优化了错误提示的字符串格式，让输出更简洁

内容的提问来源于stack exchange，提问作者Niac Nagrom