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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音を立てない
434
11
章
例外を静かに処理する
本気かい？
log_request
から発生した
例外を静かに処理するつもり？
それって例外を
無視するってこと？
いいえ。「静かに」というのは「無視」という意味では
ありません。
例外を静かに処理するというのは、ユーザが気付かないように
例外を処理するということです。現在は、
Web
アプリケーション
を実行するとわかりにくく（正直に言うと）恐ろしいエラーペー
ジを表示してクラッシュするため、ユーザに気付かれます。
ユーザであれば
log_request
が失敗しても放っておけばい
いのですが、あなたは対応しなくてはいけません。そこで、
log_
request
から例外が投げられたときに、ユーザにはわからなく
ても自分にははっきりわかるようなコードを修正しましょう。
に答えます
Q
：
try/except
はコードを読みずらくわかりにくくするだけではないのですか？
A
：確かに、この章の例では、最初はわかりやすい
3
行のコードだったのに、最初の
3
行とは一見関係なさそうなコードを
7
行追加してい
ます。しかし、例外が起こりそうなコードを守ることは重要で、一般に
try/except
はその最善の手段だと考えられています。慣
れてくると、脳が
try
ブロックに含まれる重要な部分（実際に作業を行うコード）を発見し、例外を処理する
except
ブロックを無視するよう
になります。
try/except
を使うコードを理解したいなら、まず
try
ブロックを読んでコードが実行することを理解してから、問題が発 ...
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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.