如何修复所需的位置参数？

Question

我在一个员工管理系统上工作，遇到了一个职位争论的问题。我对编码相当陌生，这是一个课堂项目。我已经阅读了一些教程和书籍，但我不断发现以下错误：

Traceback (most recent call last):
  File "C:\Users\jmcra\Desktop\CPT200\Employment Management System - Functionality 4.1.py", line 152, in <module>
    searchEmployeeSSN()
TypeError: searchEmployeeSSN() missing 1 required positional argument: 'isForEdit'

我试过几种补救办法，但只会导致更多的错误。有人能帮我吗

1. 理解这意味着什么，并且
2. 解决我的个人情况

非常感谢您的帮助

#initialize list to store employee' information
employee_info = [ ]
#initialize global variable to save the SSN
employeeSSN = 0
#initialize global variable to save the index of the found record
employeeIndex = 0
#clear the screen
def cls():
    print('\n' * 50)

#displaythe employee information in the required format
def employeeFormatedInfo(name, ssn, phone, email, salary):
    print('')
    print('--------------- {0:s} --------------------'.format(name))
    print('SSN: {0:s}'.format(ssn))
    print('Phone: {0:s}'.format(phone))
    print('Email: {0:s}'.format(email))
    print('Salary: ${0:s}'.format(salary))
    print('------------------------------------------')
    print('')

#view all employees in the system
def viewEmployeeInfo():
    cls()
    print('------------------------------------------')
    print('          View all employees\n')
    print('------------------------------------------\n')
    if(len(employee_info)==0):
        print('No employees entered.\n')
    else:
        for i in range(0, len(employee_info)):
            line = employee_info[i].split(',')
            employeeFormatedInfo(line[0], line[1], line[2], line[3], line[4])
    input('Press any button to go to Main Menu')
    cls()

#add employee
def addEmployee():
    cls()
    print('-------------------------------------------')
    print('            Add Employee')
    print('-------------------------------------------\n')
    try:
        #users can enter employee Name, SSN, Phone, Email and Salary
        name=input('Employee Name: ')
        ssn=input('Employee SSN: ')
        phone=input('Employee phone number: ')
        email=input('Employee email: ')
        salary=input('Employee salary: $')
        line = name +',' +ssn +',' +phone +',' +email +',' +salary
        index = len(employee_info)
        employee_info.insert(index, line)
    except:
        cls()
        addEmployee()
    print('\nEmployee info has been added!!\n')
    print('--------------------------------------------\n')
    try:
        #users can add new employee or return to Main Menu
        option=input('Enter q/Q to return to Main Menu or A to add another employee')
        if option.lower() == 'q':
            cls()
        else:
            cls()
            addEmployee()
    except:
        cls()
        addEmployee()
#display the Main Menu
def printOptions():
    print('--------- Employee Management System -------\n')
    print('There are ({0:2d} ) employees in the system.'.format(len(employee_info)))
    print('--------------------------------------------\n')
    print('1. View all employees\n')
    print('2. Add new employee\n')
    print('3. Search employee by SSN\n')
    print('4. Edit employee information\n')
    #check the user choice
    try:
        answer=int(input('Please enter your choice by number: '))
    except ValueError:
        print('Not a number')
        return 100
    print('--------------------------------------------\n')
    return answer

def searchEmployeeSSN(isForEdit):
    cls()
    print('--------------------------------------------\n')
    print('        Search for Employee by SSN\n')
    print('--------------------------------------------\n')
    if(len(employee_info)==0):
        input('No employee in the list.\n')
        cls()
    else:
        try:
            ssn=input('Enter SSN to search for employee or q/Q to exit to Main : ')
            global employeeSSN
            employeeSSN = ssn
            if ssn.lower() == 'q':
                return 0

        except ValueError:
            searchEmployeeSSN(0)
    for i in range(0, len(employee_info)):
        line = employee_info[i].split(',')
        if(line[1] == ssn):
            global employeeIndex
            employeeIndex = i
            employeeFormatedInfo(line[0], line[1], line[2], line[3], line[4])
            break
        else:
            print('\n       No employees with that SSN.\n')
            return 0
        try:
            if (isForEdit == 0):
                option=input('Enter q/Q to exit or any key to add another employee:')
                if option.lower() == 'q':
                    cls()
                else:
                    searchEmployeeSSN(0)
        except:
            cls()

def editEmployeeInfo():
    cls()
    #reuse the searchEmployeeSSN
    result = searchEmployeeSSN(1)
    if(result != 0):
        name=input('Employee new Name: ')
        phone=input('Employee new phone number: ')
        email=input('Employee new email: ')
        salary=input('Employee new salary: $')
        #delete the old information
        del employee_info[employeeIndex]
        line = name +',' +employeeSSN +',' +phone +',' +email +',' +salary
        #add the new information
        employee_info.insert(employeeIndex, line)
        input('\nEmployee information has been updated.  Please press any key to go to the Main Menu.\n')

while True:
    cls()
    mode = printOptions()
    if mode == 1:
        cls()
        viewEmployeeInfo()
    if mode == 2:
        cls()
        addEmployee()
    if mode == 3:
        cls()
        searchEmployeeSSN()
    if mode == 4:
        cls()
        editEmployeeInfo()

Answer 1

一,。理解这意味着什么

让我们来分析一下你遇到的错误

TypeError: searchEmployeeSSN() missing 1 required positional argument: 'isForEdit'

这是一个与函数searchEmployeeSSN相关的错误。参数是调用函数时传递给函数的值，因此我们需要查看调用函数的位置

在Python中，您可以通过在函数名后面加上一些括号来调用函数，如：searchEmployeeSSN()。那么这有什么不对呢？参数放在括号内，错误消息告诉您代码“searchEmployeeSSN()”缺少1个参数

您这样定义函数：

def searchEmployeeSSN(isForEdit):
    ...

这里，searchEmployeeSSN有一个名为isForEdit的参数。当您使用参数searchEmployeeSSN(5)调用函数时，会为参数isForEdit赋值

您还可以为以下参数指定默认值：

def searchEmployeeSSN(isForEdit=10):
    ...

未给定默认值的参数称为位置参数，因为它们仅根据传递给函数的参数的位置赋值；在您的例子中，isForEdit是第一个参数，因此被分配第一个参数的值。位置参数是必需的，因为否则Python将不知道分配给它们什么值

给定默认值的参数称为关键字参数，因为它们也可以使用参数名称指定值：

def f(x, m=5, c=0):
    return m * x + c

f(10) # 50
f(10, 6) # 60
f(10, m=6) # 60
f(10, c=5) # 55

二,。解决你的问题

我希望你已经知道你需要做什么了。在底部的while True块中，在不传递任何参数的情况下调用searchEmployeeSSN()。必须在此处传递参数或更改函数，使其没有位置参数

我还建议对表示是/否、真/假类型值的变量使用布尔值。在Python中，可以使用值True和False

Answer 2

def searchEmployeeSSN(isForEdit):
searchEmployeeSSN()

这两条线不一致。您将函数定义为需要一个参数，但调用它时却没有参数

根据您的情况，有几种方法可以解决此问题

1. 也许最简单的方法就是简单地传递一个参数。您已经在多个地方这样做了，尽管您传递了1和0，而不是True和False，这是您可能希望解决的问题
2. 您还可以给参数一个默认值（对于最可能的情况），类似于def searchEmployeeSSN(isForEdit = False):