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初来乍到小菜鸟

请各位帮忙看看哪里代码错了。谢谢了


代码：
class User():
    def __init__(self,first_name,last_name):
        self.first_name = first_name
        self.last_name = last_name

    def describe_user(self):
        print("User's first name is " + first_name.title() + ".")
        print("User's last name is " + last_name.title() + ".")

    def greet_user(self):
        print("Hello "+ first_name.title() + " " + last_name.title() + "!")


my_user = User("bob","jims")
my_user.describe_user()
my_user.greet_user()

错误提示：Traceback (most recent call last):
  File "E:/python/class_user.py", line 15, in <module>
    my_user.describe_user()
  File "E:/python/class_user.py", line 7, in describe_user
    print("User's first name is " + first_name.title() + ".")
NameError: name 'first_name' is not defined

最佳答案

月排行榜 / 总排行榜

冬雪雪冬

2017-8-23 17:48:56

缺少self

1. class User():
   
2.     def __init__(self,first_name,last_name):
   
3.         self.first_name = first_name
   
4.         self.last_name = last_name
   
5. 
   
6.     def describe_user(self):
   
7.         print("User's first name is " + self.first_name.title() + ".")
   
8.         print("User's last name is " + self.last_name.title() + ".")
   
9. 
   
10.     def greet_user(self):
    
11.         print("Hello "+ self.first_name.title() + " " + self.last_name.title() + "!")
    

复制代码

跳转到最佳答案楼层

冬雪雪冬

缺少self

1. class User():
   
2.     def __init__(self,first_name,last_name):
   
3.         self.first_name = first_name
   
4.         self.last_name = last_name
   
5. 
   
6.     def describe_user(self):
   
7.         print("User's first name is " + self.first_name.title() + ".")
   
8.         print("User's last name is " + self.last_name.title() + ".")
   
9. 
   
10.     def greet_user(self):
    
11.         print("Hello "+ self.first_name.title() + " " + self.last_name.title() + "!")
    

复制代码

hustlin

错误提示是变量没定义，回去找就会发现是因为你引用的是类变量的属性，应该用self.first_name，因为是类里面定义的方法。解决方案就是楼上的代码。

初来乍到小菜鸟

hustlin 发表于 2017-8-23 18:38
错误提示是变量没定义，回去找就会发现是因为你引用的是类变量的属性，应该用self.first_name，因为是类里 ...

嗯，明白了，谢谢你

初来乍到小菜鸟

冬雪雪冬 发表于 2017-8-23 17:48
缺少self

好的，明白了，谢谢你