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Pythonファイル入出力用メモ

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業務でcsv加工系の処理を書きそうなのでカンペ作成"φ(・ェ・o)~メモメモ
2系のつもりで3系混ざっていたらすみません。

open関数

file = open("read.txt", "r", "UTF-8")
引数 必須 説明
$1 ファイル名
$2 - モード
$3 - 文字コード

モードのオプションは複数指定が可能。

タイプ 説明
r 読み取り専用
a 追記、ファイルがない場合は生成
t テキストモード(default)
b バイナリモード

withステートメントを使用すると、自動でclose()が可能。

with open('text_file.txt') as file:
    print(file.read())

連結

# join関数で簡単に連結
"-".join(["foo", "bar", "baz"])
>>> 'foo-bar-baz'

変換

# "%s"で置き換えも楽チンに
"%s, %s, %s!" % ("one", "two", "three")
>>> 'one, two, three!'
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