Question

我正在制作class个播放列表，其中包含许多相同类型的播放列表。

class playlist(object):
      def __init__(self,name):
         self.name = name

我想实例化它们传递用户：

      def hard_rock(self,user):
         self.user = user
         #query and retrieve data from music API
         #return playlist

      def pop_rock(self,user):
         self.user = user
         #query and retrieve data from music API
         #return playlist

      #and so on

创建实例：

r = playlist('rock')
r.hard_rock('user1')

这是构建和实例化类的逻辑方式吗？

Answer 1

如果我理解正确，您需要播放列表和用户

class Playlist(object):
    def __init__(self, name):
        self.name = name
        self.liked_by = list()

    @classmethod
    def get_genre(cls, genre):
        # this relies on no instance of this class
        pass
        # return api data...

class User(object):
     def __init__(self, name):
         self.name = name

     def likes_playlist(self, playlist):
         playlist.liked_by.append(self.name)

然后，一些例子

playlists = list()
hard_rock = Playlist('hard_rock')

joe = User('joe')
joe.likes_playlist(hard_rock)

playlists.append(hard_rock)
playlists.append(Playlist('pop_rock'))

country = Playlist.get_genre('country')

Answer 2

如果播放列表是应用程序的核心组件（使用类继承的非常简单的示例），那么这样的事情是可能的。

>>> class playlist:
...     def __init__(self,name, user):
...         self.name = name
...         self.user = user
... 
>>> class hardrock(playlist):
...     def __init__(self,name, user):
...         playlist.__init__(self, name, user)
... 
>>> test = hardrock('my_awesome_hardrock_list', 'my_awesome_username')
>>> print test.name
my_awesome_hardrock_list
>>> print test.user
my_awesome_username

您可以开始仅为用户使用字符串，然后将其替换为真实对象，并在播放列表和用户之间添加某种关系。请参阅cricket_007关于更多想法的建议。

Python - 创建并实例化类

2 个答案: