Python程序中program方法的while循环无法终止问题求助

我正在开发一款支持添加、删除、列出数据的Python程序，当前遇到program方法内的while循环无法终止的问题。即使在addRecord函数中输入姓名，程序仍会输出“pls enter a valid number again ”。该问题在编写addRecord函数之前就已存在，附上相关代码，寻求解决建议或问题原因解释。

import re
#list of user information
list_id = []
list_name = []
list_surname = []
list_age = []
list_nationalid = []
list_mail = []

class Record:

    def __init__(self,programName):
        self.programName = programName
        self.loop = True
        print("welcome {}.".format(programName))

    def program(self):
        while True: #the loop gonna keep ask if input is not a correct number 
            try:
                userInput = int(input ("what you want to do?\n1-addRecord\n2-removeRecord\n3-listRecord\n4-exitRecord\n"))
                if userInput < 5 and userInput > 0: 
                    self.menu(userInput)
                    break 
                else:
                    print("pls enter a valid number")
            except Exception :
                print("pls enter a valid number again ")

    def menu(self,userInput):
        self.userInput = userInput
        if  userInput == 1:
            print("addRecord is opening")
            self.addRecord()
        if userInput == 2:
            print("removeRecord is opening")
            self.removeRecord()
        if userInput == 3:
            print("list Record are opening")
            self.listRecord()
        if userInput == 4:
            self.exitRecord()

    def addRecord(self):
        while True:
            user_name = input("pls enter your name")
            if user_name == re.findall("[^a-z]"):
                list_name.append(user_name)
                print ("addRecord_name worked")
                break
            else:
                print ("enter a valid name")
        while True:
            user_surname = input("pls enter your name")
            if user_surname == re.findall("[^a-zA-E]"):
                list_surname.append(user_surname)
                print ("addRecord_surname worked")
                break
            else:
                print ("enter a valid surname")
        while True:
            user_age = input("pls enter your age")
            if user_age == re.findall("[^0-9]"):
                list_age.append(user_age)
                print ("addRecord_age worked")
                break
            else:
                print ("enter a valid age")
        while True:
            user_nationalid = input("pls enter your national id")
            if user_name == re.findall("[^0-9]"):
                list_nationalid.append(user_nationalid)
                print ("addRecord_nationalid worked")
                break
            else:
                print ("enter a valid national id")
        while True:
            user_mail = input("pls enter your name")
            if user_name == re.search("@" and ".com" , user_mail):
                list_mail.append(user_mail)
                print ("addRecord_mail worked")
                break
            else:
                print ("enter a valid national id")

    def removeRecord(self):
        pass
    def listRecord(self):
        pass
    def backToMenu(self):
        pass
    def exitRecord(self):
        pass

System = Record("admin")
System.program() #its for keep working `program` 

问题原因及修复建议 #

1. program方法循环终止问题 #

原代码中program方法的while True循环在调用self.menu(userInput)后执行了break，这会导致执行完一次操作后直接退出主循环，无法回到主菜单继续操作。如果期望执行完操作后返回主菜单，需要删除这个break语句，修改后的program方法如下：

def program(self):
    while True:
        try:
            userInput = int(input ("what you want to do?\n1-addRecord\n2-removeRecord\n3-listRecord\n4-exitRecord\n"))
            if userInput < 5 and userInput > 0: 
                self.menu(userInput)
                # 移除break，执行完操作后回到循环开头，重新显示主菜单
            else:
                print("pls enter a valid number")
        except Exception :
            print("pls enter a valid number again ")

同时，exitRecord方法需要实现终止循环的逻辑，比如：

def exitRecord(self):
    print("Exiting program...")
    exit()

2. addRecord方法中正则验证的多处错误 #

这是导致输入姓名后一直提示错误的核心原因，具体问题及修复：

• 正则使用错误：re.findall需要传入正则表达式和待匹配的字符串，且正则规则写反。比如验证姓名应该匹配全小写字母，而不是非小写字母，建议用re.fullmatch判断整个字符串是否符合规则。
• 变量混淆：验证身份证号时错误使用user_name进行判断，应该用user_nationalid。
• 输入提示错误：输入姓氏时提示“pls enter your name”，邮箱输入提示也是错误的，需要修正。
• 邮箱验证逻辑错误：re.search("@" and ".com" , user_mail)逻辑错误，且错误地用user_name判断匹配结果，应该用正则匹配合法邮箱格式。

修改后的addRecord方法示例：

def addRecord(self):
    # 验证姓名：仅允许小写字母
    while True:
        user_name = input("pls enter your name: ")
        if re.fullmatch(r'[a-z]+', user_name):
            list_name.append(user_name)
            print("addRecord_name worked")
            break
        else:
            print("enter a valid name (only lowercase letters)")
    
    # 验证姓氏：允许大小写A-E的字母
    while True:
        user_surname = input("pls enter your surname: ")
        if re.fullmatch(r'[a-zA-E]+', user_surname):
            list_surname.append(user_surname)
            print("addRecord_surname worked")
            break
        else:
            print("enter a valid surname (only letters A-E, case insensitive)")
    
    # 验证年龄：仅允许数字
    while True:
        user_age = input("pls enter your age: ")
        if re.fullmatch(r'[0-9]+', user_age):
            list_age.append(user_age)
            print("addRecord_age worked")
            break
        else:
            print("enter a valid age (only numbers)")
    
    # 验证身份证号：仅允许数字
    while True:
        user_nationalid = input("pls enter your national id: ")
        if re.fullmatch(r'[0-9]+', user_nationalid):
            list_nationalid.append(user_nationalid)
            print("addRecord_nationalid worked")
            break
        else:
            print("enter a valid national id (only numbers)")
    
    # 验证邮箱：包含@和.com
    while True:
        user_mail = input("pls enter your mail: ")
        if re.fullmatch(r'.+@.+\.com', user_mail):
            list_mail.append(user_mail)
            print("addRecord_mail worked")
            break
        else:
            print("enter a valid mail (must contain @ and .com)")

其他优化建议 #

• 建议用一个字典或类实例来存储用户信息，而不是多个独立的列表，更便于管理。
• 异常处理尽量精确，比如只捕获ValueError（输入无法转为整数的情况），而不是捕获所有Exception。

内容的提问来源于stack exchange，提问作者fethullah cücü