def main()

     name = input ("Please enter your name")

     print ("your name is",name)

在这个程序中(写入python IDLE)当我运行它,并输入我的名字我收到这个错误消息.

Traceback (most recent call last):

 File "C:\Users\********\Documents\PYTHON\hello world.py",line 66,in ?

   main()

  File "C:\Users\********\Documents\PYTHON\hello world.py",line 5,in main

    name = input ("Please enter your name")

  File "<string>",line 0,in ?

NameError: name 'Jim' is not defined

没有定义是什么意思？吉姆是输入,我如何定义输入,而可能是任何字母的混合？