March 2023
Intermediate to advanced
384 pages
5h 30m
Japanese
Content preview from ロバストPython ―クリーンで保守しやすいコードを書く
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2章Pythonデータ型入門
保守性の高いPythonコードを書くためにはデータ型の性質を熟知し、意識的にデータ型を使い分けなければならない。まずデータ型とは何か、なぜ重要なのかを説明する。そして、Pythonの型システムがコードベースのロバストネスにどのような影響を与えるのかについて説明する。
2.1 データ型には何が含まれているか
一旦読むのを止めて質問に答えてみてほしい。数値、文字列、テキスト、ブール値などに言及せずにデータ型について説明できるだろうか。
これは誰でも簡単に解答できる問題ではない。Pythonのように変数のデータ型を明示的に宣言する必要がない言語では何が利点なのか説明するのは難しいだろう。
データ型とはコミュニケーション手段である。データ型は情報を伝達する。ユーザとコンピュータが推論できる表現を提供する。この表現を2つの側面に分けて考える。
- 機械的な表現
- データ型は、Python自体に振る舞いと制約を伝える。
- 意味論的な表現
- データ型は、他の開発者に振る舞いと制約を伝える。
もう少し詳しく説明しよう。
2.1.1 機械的な表現
本質的にはコンピュータではバイナリコードがすべてだ。プロセッサはPythonを話さない。プロセッサが理解するのはバイナリだけだ。コンピュータのメモリも同様だ。
メモリが次のような状態だったとしよう。
0011001010001001000101001001000100100010000010101 0010101010101000000111111110010010100111110100100 0100100010010100101011101111011010101010101010101 010100000100000101010100 ...
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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.