使用 input() 时出现 NameError [重复]

Question

那么我在这里做错了什么？

answer = int(input("What is the name of Dr. Bunsen Honeydew's assistant?"))
if answer == ("Beaker"):
    print("Correct!")
else:
    print("Incorrect! It is Beaker.")

但是，我只得到

  Traceback (most recent call last):
  File "C:\Users\your pc\Desktop\JQuery\yay.py", line 2, in <module>
    answer = int(input("What is the name of Dr. Bunsen Honeydew's assistant?"))
  File "<string>", line 1, in <module>
      NameError: name 'Beaker' is not defined

Answer 1

您在 python 2 中使用 input 而不是 raw_input，它将输入评估为 python 代码。

answer = raw_input("What is the name of Dr. Bunsen Honeydew's assistant?")
if answer == "Beaker":
   print("Correct!")

input() 等价于eval(raw_input())

• input
• raw_input

您还试图将“Beaker”转换为整数，这没有多大意义。

 

你可以像这样用raw_input替换你脑海中的输入：

answer = "Beaker"
if answer == "Beaker":
   print("Correct!")

还有input:

answer = Beaker        # raises NameError, there's no variable named Beaker
if answer == "Beaker":
   print("Correct!")

Answer 2

您为什么要使用 int 并在输入时期望字符串？使用 raw_input 对于您的情况，它会将 answer 的所有可能值捕获为字符串。所以在你的情况下，它会是这样的：

answer = raw_input("What is the name of Dr. Bunsen Honeydew's assistant?")
#This works fine and converts every input to string.
if answer == 'Beaker':
   print ('Correct')

或

如果您只使用input。期望字符串的“答案”或“答案”。喜欢：

>>> answer = input("What is the name of Dr. Bunsen Honeydew's assistant?")
What is the name of Dr. Bunsen Honeydew's assistant?'Beaker'#or"Beaker"
>>> print answer
Beaker
>>> type(answer)
<type 'str'>

类似于在input 中使用int，像这样使用它：

>>> answer = input("What is the name of Dr. Bunsen Honeydew's assistant?")
What is the name of Dr. Bunsen Honeydew's assistant?12
>>> type(answer)
<type 'int'>

但是如果你输入：

>>> answer = input("What is the name of Dr. Bunsen Honeydew's assistant?")
What is the name of Dr. Bunsen Honeydew's assistant?"12"
>>> type(answer)
<type 'str'>
>>> a = int(answer)
>>> type(a)
<type 'int'>