September 2014
Intermediate to advanced
332 pages
6h 48m
Japanese
Content preview from Python文法詳解
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
289
7.8 特殊メソッド
送出すると、
__getattr__()
が呼び出されます。
パフォーマンス上の理由から、特殊メソッドが暗黙的に呼び出される場合は、
__
getattribute__()/__getattr__()
メソッドは呼び出されません。例えば、
spam + ham
という
式を評価すると
spam.__add__(ham)
が呼び出されますが、このとき、
__add__
メソッドは
__
getattribute__()
メソッドを経由せず、直接実行されます。
__setattr__(
self
,
name
,
value
)
属性
name
に、値
value
を設定する時に呼び出されます。
__setattr__()
メソッド中で値を設定するとき、
self.name = value
と書くと無限ループとな
るので、
super().__setattr__(name, value)
のように、基底クラスの
__setattr__()
を呼び出
して設定します。
__delattr__(
self
,
name
)
name
で指定された属性を削除する時に呼び出されます。属性名が無効なら
AttributeError
例外
を送出します。
__dir__(
self
)
dir(object)
から呼び出され、オブジェクトの属性名の一覧を、ソートして返します。
7.8.12
コンテナインターフェース
辞書やリストなど、
Python
のコンテナとして振る舞うオブジェクトを実装するメソッドです。
表
7-16
コンテナインターフェース
式 メソッド
len(obj) ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.