[Python] df 열 반환

Reference

Pandas In Action

1. df 열 반환

import pandas as pd

nba = pd.read_csv(
    './Data/nba.csv',
    parse_dates = ['Birthday']  # 'Birthday'의 데이터 유형을 날짜/시간(datetime)으로 강제 변환
)
nba

	Name	Team	Position	Birthday	Salary
0	Shake Milton	Philadelphia 76ers	SG	1996-09-26	1445697
1	Christian Wood	Detroit Pistons	PF	1995-09-27	1645357
2	PJ Washington	Charlotte Hornets	PF	1998-08-23	3831840
3	Derrick Rose	Detroit Pistons	PG	1988-10-04	7317074
4	Marial Shayok	Philadelphia 76ers	G	1995-07-26	79568
…	…	…	…	…	…
445	Austin Rivers	Houston Rockets	PG	1992-08-01	2174310
446	Harry Giles	Sacramento Kings	PF	1998-04-22	2578800
447	Robin Lopez	Milwaukee Bucks	C	1988-04-01	4767000
448	Collin Sexton	Cleveland Cavaliers	PG	1999-01-04	4764960
449	Ricky Rubio	Phoenix Suns	PG	1990-10-21	16200000

450 rows × 5 columns

1-1. df 단일 열 선택 :: df.col_name or df[‘col_name’]

nba.Name # nba의 'Name'열

0        Shake Milton
1      Christian Wood
2       PJ Washington
3        Derrick Rose
4       Marial Shayok
            ...      
445     Austin Rivers
446       Harry Giles
447       Robin Lopez
448     Collin Sexton
449       Ricky Rubio
Name: Name, Length: 450, dtype: object

nba['Name'] # nba의 'Name'열

0        Shake Milton
1      Christian Wood
2       PJ Washington
3        Derrick Rose
4       Marial Shayok
            ...      
445     Austin Rivers
446       Harry Giles
447       Robin Lopez
448     Collin Sexton
449       Ricky Rubio
Name: Name, Length: 450, dtype: object

1-2. df 다중 열 선택 :: df[[‘col_name1’, ‘col_name2’]]

nba[['Name','Team']] # nba의 'Name', 'Team' 열

	Name	Team
0	Shake Milton	Philadelphia 76ers
1	Christian Wood	Detroit Pistons
2	PJ Washington	Charlotte Hornets
3	Derrick Rose	Detroit Pistons
4	Marial Shayok	Philadelphia 76ers
…	…	…
445	Austin Rivers	Houston Rockets
446	Harry Giles	Sacramento Kings
447	Robin Lopez	Milwaukee Bucks
448	Collin Sexton	Cleveland Cavaliers
449	Ricky Rubio	Phoenix Suns

450 rows × 2 columns