如何基于用户输入重启Python脚本？解决return/continue语法错误

核心问题分析 #

你遇到的报错本质是return只能在函数内使用，continue必须在循环结构里生效。要实现查询余额后重启脚本的需求，最直接的方式是把整个ATM操作逻辑封装成循环或者函数，通过循环控制流程的重复执行。同时原脚本还有个隐藏问题：余额和取款金额是字符串类型，直接用</>比较会出错，需要先转成数值类型。

修改后的完整代码 #

import time
import sys

def atm_operation():
    pin = "5327"
    # 把余额转成float类型，方便后续金额比较
    balance = 67.32
    pin_attempt = input("Please enter pin:  ")
    
    if pin_attempt == pin:
        deposit_or_withdraw = input("Please press 1 to deposit cash, 2 to withdraw cash or 3 to check balance.  ")
        
        if deposit_or_withdraw == "1":
            deposit_value = input("How much cash would you like to deposit?  ")
            # 校验输入是否为合法数字
            try:
                deposit_value = float(deposit_value)
            except ValueError:
                print("Invalid amount, please try again.")
                return True  # 返回True表示需要重新执行
            
            print("Processing.")
            time.sleep(0.5)
            print("Processing..")
            time.sleep(0.5)
            print("Processing...")
            time.sleep(0.5)
            print("Processing.")
            time.sleep(0.5)
            print("Processing..")
            time.sleep(0.5)
            print(f"Successfully deposited £{deposit_value} into account")
            return False  # 返回False表示退出
        
        elif deposit_or_withdraw == "2":
            withdraw_amount = input("How much cash would you like to withdraw? ")
            try:
                withdraw_amount = float(withdraw_amount)
            except ValueError:
                print("Invalid amount, please try again.")
                return True
            
            if withdraw_amount <= balance:
                print(f"Successfully withdrawn £{withdraw_amount} from your account. Please take your cash")
                time.sleep(3)
                print("💵💵💵")
                return False
            else:
                print(f"You cannot withdraw more cash than is in your account (£{balance}), please re enter your pin to continue.")
                return True
        
        elif deposit_or_withdraw == "3":
            print(f"You currently have £{balance} available in your account.")
            carry_on = input("If you would like to withdraw or deposit cash please press 1, if you would like to exit please press 2.")
            if carry_on == "1":
                return True  # 返回True触发重新执行
            elif carry_on == "2":
                print("Thank you, please don't forget to take your card.")
                return False
            else:
                print("Invalid input, please try again.")
                return True
        else:
            print("Invalid option, please try again.")
            return True
    else:
        print("Incorrect pin.")
        return True

# 主循环：只要atm_operation返回True，就重新执行整个流程
while True:
    should_restart = atm_operation()
    if not should_restart:
        sys.exit()

关键修改点说明 #

• 函数封装+循环控制：把所有ATM操作逻辑放进atm_operation函数，函数返回True表示需要重启流程，返回False表示退出。主循环通过判断返回值决定是否重复执行。
• 类型修复：把余额从字符串改成float，同时对存款、取款金额做类型转换和异常捕获，避免非数字输入导致报错。
• 重启逻辑实现：查询余额后输入1时，函数返回True，主循环会再次调用atm_operation，等价于“重启脚本”；其他退出场景返回False，终止循环。

内容的提问来源于stack exchange，提问作者Miles Price