输入错误

Question

我试图在蟒蛇一个简单的计算器，但我似乎得到的输入错误，每当我尝试运行它：

while True: 
print("please choose one of these available options:\n\"add, subtract, multiply, divide, quit\"\ntype in exactly as shown or the calculator won't work"); 
choice = input(); 
if(choice == "quit"): 
    break; 
elif(choice == "divide"): 
    num1 = float(input("Please enter a number:")); 
    num2 = float(input("Please enter another number:")); 
    output = num1/num2; 
    print("The answer is:", output); 
elif(choice == "multiply"): 
    num1 = float(input("Please enter a number:")); 
    num2 = float(input("Please enter another number:")); 
    output = num1*num2; 
    print("The answer is:", output); 
elif(choice == "subtract"): 
    num1 = float(input("Please enter a number:")); 
    num2 = float(input("Please enter another number:")); 
    output = num1-num2; 
    print("The answer is:", output); 
elif(choice == "add"): 
    num1 = float(input("Please enter a number:")); 
    num2 = float(input("Please enter another number:")); 
    output = num1+num2; 
    print("The answer is:", output); 
else: 
    print("Invalid Input. Try again"); 

当我运行代码，解释只是表明：NameError: name '...' is not defined每当我输入内容时（用输入替换省略号）。

有人可以请看看我是否做了任何输入错误，因为这是唯一不行的。

谢谢

Answer 1

你好user8311329，

问题

当您使用字符串作为输入，因此使用raw_input()功能。并且你使用的所有程序都是;，所以python提供了用;(colon)来执行程序的功能。

解决方案

试试这个代码，

while True: 
    print("please choose one of these available options: \n1. Add \n2. Subtract \n3. Multiply \n4. Divide \n5. Quit \nType in exactly as shown or the calculator won't work") 
    choice = str(raw_input("From above choice any one option: ")) 

    if(choice == "quit"): 
     break 

    elif(choice == "divide"): 
     num1 = float(input("Please enter a number:")) 
     num2 = float(input("Please enter another number:")) 
     output = num1/num2 
     print "The answer is:",output 

    elif(choice == "multiply"): 
     num1 = float(input("Please enter a number:")) 
     num2 = float(input("Please enter another number:")) 
     output = num1*num2 
     print "The answer is:",output 

    elif(choice == "subtract"): 
     num1 = float(input("Please enter a number:")) 
     num2 = float(input("Please enter another number:")) 
     output = num1-num2 
     print "The answer is:",output 

    elif(choice == "add"): 
     num1 = float(input("Please enter a number:")) 
     num2 = float(input("Please enter another number:")) 
     output = num1+num2 
     print "The answer is:",output 

    else: 
     print("Invalid Input. Try again") 

我给的建议，例如，如果任何其他用户运行这个使用你的应用程序，这样这个人有什么不明白的输入准确输入所以代码编写高效和完善，所以其他用户容易理解，并给出建议不使用此代码的字符串插入，但使用数字输入的选择像我举例（我不给只是简单的例子，你也添加更多的验证输入），

while True: 
    print("please choose one of these available options: \n1. Add \n2. Subtract \n3. Multiply \n4. Divide \n5. Quit \nType in exactly as shown or the calculator won't work") 
    try: 
     choice = input("From above choice any one option: ") 

     if(choice == 1): 
      num1 = float(input("Please enter a number:")) 
      num2 = float(input("Please enter another number:")) 
      output = num1+num2 
      print "The answer is:",output,"\n" 

     elif(choice == 2): 
      num1 = float(input("Please enter a number:")) 
      num2 = float(input("Please enter another number:")) 
      output = num1-num2 
      print "The answer is:",output,"\n" 

     elif(choice == 3): 
      num1 = float(input("Please enter a number:")) 
      num2 = float(input("Please enter another number:")) 
      output = num1*num2 
      print "The answer is:",output,"\n" 

     elif(choice == 4): 
      num1 = float(input("Please enter a number:")) 
      num2 = float(input("Please enter another number:")) 
      output = num1/num2 
      print "The answer is:",output,"\n" 


     elif(choice == 5): 
      break 

     else: 
      print "Invalid Input. Try again\n" 
    except: 
     print "Invalid Input. Try again...\n" 

我希望我的回答有帮助。
如果有任何查询请这么评论。

Answer 2

只是改变输入（），到raw_input（）。与输入（）相比，raw_input（）将输入作为字符串输入，而输入（）会决定你的输入。

也，你可以把打印里面输入：

choice = raw_input("please choose one of these available options:\n\"add, subtract, multiply, divide, quit\"\ntype in exactly as shown or the calculator won't work") 

也，你并不需要 ';'在每一行的蟒蛇到底