June 2024
Intermediate to advanced
200 pages
4h 46m
Japanese
Content preview from Python2年生 データ分析のしくみ 第2版 体験してわかる！会話でまなべる！
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Chapter
2
54
データを眺める
まず先頭の5行だけ確認してみましょう。このデータは、もともと数が少ないのであま
り変化はありませんが、データが大量にあるときに便利な機能です（リスト
2.9）。
import pandas as pd
df = pd.read_csv("test.csv", index_col=0)
df.head()
05
LESSON
ここではさまざまな角度からデータを「眺める」方法を解説します。
デ ー タをざっくりと
眺める
データが読み込めたら、まずはざっくりと眺めてみよう。
データ分析の前に、データが正しく読み込まれているかを確認するん
だ。
眺める？
料理する前に、材料がちゃんとあるか確認するみたいなことね。
【入力プログラム】リスト 2.9
55
データをざっくりと眺める
LESSON
05
次は、列名がちゃんと入力されているか確認しましょう（リスト2.10）。
df.columns
Index(['国語', '数学', '英語', '学生番号'], dtype='object')
※シングルクォーテーションが使われていますが、これも文字列です。
インデックス名も確認しましょう（リスト2.11）。
df.index
Index(['A太', 'B介', 'C子', 'D郎', 'E美', 'F菜
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