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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81
データを平らに均（なら）す
LESSON
08
平均値を求める
「平均値」とは、「凹凸のあるデータの、凹凸を平らに均（なら）した値」です。
平均値
平均値
計算では、「平均値 = データの合計 ÷ データの個数」で求めます。
Pythonでは、平均値をどのように求めるのかを、例を使って見てみましょう。
ここに、ある
2つのクラスの英語の成績データがあったとして、それぞれのクラスの平
均値を求めます（リスト
3.1）。
凹凸のあるデータ
の
凹凸を平らに均し
たものが
平均値
凹凸を平らに
するのね！
イメージできた
かな？
Chapter
3
82
import pandas as pd
data = {
"A
クラス" : [82,89,93,85,76],
"B
クラス" : [100,62,82,70,86]
}
df = pd.DataFrame(data)
df
数がこのくらい少なければ、眺めるだけでもわかりますが、たくさんあった場合は大変
です。そこで、各クラスを
1つの数値に要約してみましょう。「データフレーム["列名
"].mean()」と命令すると、列データの平均値が求まります。
• 必要なライブラリ：pandas
•
命令
df["列名"].mean()
• 出力：列データの平均値
「Aクラス」と「Bクラス」の平均値を表示してみましょう ...
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