NameError: name ' ' is not defined

Question

我有这个程序，我希望它运行通过每个菜单选项。基本上用户登录，菜单出现并按下一个工作。但是，当我按 2 时，它告诉我 'Search Student is not defined' 我不明白它在说什么。我试图在程序中移动该函数，但如果这样做，我会遇到其他错误。我正在寻找构建它的正确方法。功能是否在菜单之前？登录后？那我应该怎么打电话给他们呢？

choice = input
def PrintMenu():
    print("\n*******************")
    print("\n School menu system")
    print("\n*******************")
    print("  [1] Add Student")
    print("  [2] Search Student")
    print("  [3] Find Report")
    print("  [4] Exit")
    choice = input ("Enter a choice: ")
#while choice =='':
    if choice == '1':
        AddStudent()
    elif choice == '2':
        SearchStudent(ID)
    elif choice == '3':
        FindReport()
    elif choice == '4':
        print("\nExiting the system......\n")
        sys.exit(0)
    else:
           print ("\n not valid choice")
PrintMenu()
def SearchStudent(ID):
    with open("Students.txt", 'r') as file:
        for i in file:
            data = i.rstrip().split(",")
            if data[0] == ID:
                return "The student you require is: {} {}".format(data[2], data[1])
    return "No matches found"
search = input("Please enter a student ID: ")
print(SearchStudent(search))

Answer 1

您应该将 SearchStudent(ID) 放在主函数之前。在 Python 中，事物（例如函数）必须在 定义之前 调用它们。

主要部分必须在您要使用的功能之后。鉴于您的登录功能应该是主要功能，您必须让程序知道它。将此添加到代码的末尾：

if __name__== "__main__":
  yourMainFunction()

您的代码很可能如下所示：

def FindReport(args):
  #What it's going to do

def SearchStudent(args):
  #What it's going to do 

def AddStudent(args):
  #What it's going to do

def PrintMenu():
  #What it's going to do

def Login():
   #Your main function

if __name__ == "__main__":
   Login()

NameError: name ' ' is not defined

NameError: name ' ' is not defined

python

menu

function

procedures