August 2017
Intermediate to advanced
500 pages
12h 3m
Japanese
Content preview from PythonとJavaScriptではじめるデータビジュアライゼーション
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208
9 章 pandas によるデータのクリーニング
131 Aaron Klug
615 Albert Einstein
844 Albert Einstein
...
489 Yoichiro Nambu
773 Yoichiro Nambu
Name: name, Length: 92, dtype: object
❶ 複数行（つまり、重複した名前）を持つ
name
行グループを抽出して
Python
リストを作成する。
ゴールへの異なる道
pandas のような大きなライブラリでは通常、同じことを行う複数の方法があります。本書のノーベ
ル賞受賞者のような小さなデータセットではどの方法でも可能ですが、大きなデータセットでは性能
に大きな影響が出ることがあります。必要な処理が pandas で実行できるからといって、必ずしも効
率的というわけはありません。水面下では多くの複雑なデータ操作が行われているので、柔軟性を持
つように心がけ、非効率な方法は避けましょう。
9.4.5
データのソート
名前が重複する全行を含む
all_dupes DataFrame
ができたので、これを使って
pandas
の
sort_
values
メソッドの例を示しましょう。
pandas
は
DataFrame
と
Series
クラスのための高度な
sort_values
メソッドを提供しています。
複数の列名でソートできます。
df2 = pd.DataFrame(
{'name':['zak', 'alice', 'bob', 'mike', 'bob', ...
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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.
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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.