August 2015
Intermediate to advanced
272 pages
5h 46m
Japanese
Content preview from Think Stats 第2版 ―プログラマのための統計入門
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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.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.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.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.
41
41
3.5 DataFrame のインデックス処理
3.5
DataFrame
のインデックス処理
「
1.4
DataFrame
」で
pandas
の
DataFrame
を読み込み、それを使ってデータカ
ラムの選択と変更を行いました。今度は、行選択を行いましょう。はじめに、乱数の
NumPy
配列を作り、それを使って
DataFrame
を初期化します。
>>> import numpy as np
>>> import pandas
>>> array = np.random .randn(4, 2)
>>> df = pandas.DataFrame(array)
>>> df
0 1
0 -0.143510 0.616050
1 -1.489647 0.300774
2 -0.074350 0.039621
3 -1.369968 0.545897
デフォルトでは、行もカラムもゼロから始まりますが、カラム名を指定することが
できます。
>>> col umns = ['A', 'B']
>>> df = pandas.DataFrame(array, columns=columns)
>>> df
A B
0 -0.143510 0.616050
1 -1.489647 0.300774
2 -0.074350 0.039621
3 -1.369968 0.545897
行名も与えられます。行名の集合をインデックス（
index
）と呼びます。名前その
ものはラベル（
label
）と呼びます。
>>> index = ['a', 'b', ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
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.