March 2018
Beginner to intermediate
624 pages
16h 10m
Japanese
Content preview from Head First Python 第2版 ―頭とからだで覚えるPythonの基本
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オブジェクトは振る舞いを共有するが、
状態は共有しない
クラスからオブジェクトを生成すると、オブジェクトはクラスに書かれた振る舞い（クラスで定義し
たメソッド）を共有しますが、状態（属性）はそれぞれのコピーを持ちます。
オブジェクト
メソッド
（同じクラスから生成した
全オブジェクトが共有する）
属性
（同じクラスから生成した他の
オブジェクトは共有しない）
CountFromBy
の例を作成するうちにメソッドと属性の区別がつくようになるでしょう。
CountFromBy
で実行したいことを定義する
CountFromBy
クラスで実際に実行したいことを定義してみましょう（空のクラスは役に立
たないため）。
CountFromBy
をインクリメントカウンタにしてみましょう。デフォルトでは、このカウン
タは
0
から始まり（要求に応じて）
1
ずつ増えます。
0
以外の開始値や増分量も指定できるように
します。つまり、例えば
100
から始まり
10
ずつ増える
CountFromBy
オブジェクトを生成でき
るようになります。
（コードを書いたら）
CountFromBy
クラスができることを見直してみましょう。クラスの使
い方がわかると、
CountFromBy
コードを書く際に理解しやすくなります。ここでの最初の例
では、このクラスのデフォルトを使います。
0
から始まり、
increase
メソッドを呼び出すと要
求に応じて
1
ずつ増えます。新たに生成したオブジェクトを新しい変数
c
に代入しましょう。
注意：この新しい
CountFromBy
クラスはこれか ...
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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.