내부 조인

pandas로 데이터 조인하기

Aaren Stubberfield

Instructor

명확성을 위해

시력표를 보고 있는 안경

테이블 = DataFrames

병합 = 결합

¹ 사진: Unsplash의 David Travis

시카고 데이터 포털 데이터세트

시카고 스카이라인 이미지

¹ 사진: Unsplash의 Pedro Lastra

예시용 데이터세트

시카고 구역 지도

¹ 구역 이미지 By Alissapump, Own work, CC BY-SA 3.0

구역 데이터

wards = pd.read_csv('Ward_Offices.csv')
print(wards.head())
print(wards.shape)

  ward  alderman         address          zip
0 1     Proco "Joe" ...  2058 NORTH W...  60647
1 2     Brian Hopkins    1400 NORTH  ...  60622
2 3     Pat Dowell       5046 SOUTH S...  60609
3 4     William D. B...  435 EAST 35T...  60616
4 5     Leslie A. Ha...  2325 EAST 71...  60649
(50, 4)

인구조사 데이터

census = pd.read_csv('Ward_Census.csv')
print(census.head())
print(census.shape)

  ward  pop_2000  pop_2010  change  address          zip
0 1     52951     56149     6%      2765 WEST SA...  60647
1 2     54361     55805     3%      WM WASTE MAN...  60622
2 3     40385     53039     31%     17 EAST 38TH...  60653
3 4     51953     54589     5%      31ST ST HARB...  60653
4 5     55302     51455     -7%     JACKSON PARK...  60637
(50, 6)

테이블 병합하기

  ward  alderman         address          zip
0 1     Proco "Joe" ...  2058 NORTH W...  60647
1 2     Brian Hopkins    1400 NORTH  ...  60622
2 3     Pat Dowell       5046 SOUTH S...  60609
3 4     William D. B...  435 EAST 35T...  60616
4 5     Leslie A. Ha...  2325 EAST 71...  60649

  ward  pop_2000  pop_2010  change  address          zip
0 1     52951     56149     6%      2765 WEST SA...  60647
1 2     54361     55805     3%      WM WASTE MAN...  60622
2 3     40385     53039     31%     17 EAST 38TH...  60653
3 4     51953     54589     5%      31ST ST HARB...  60653
4 5     55302     51455     -7%     JACKSON PARK...  60637

내부 조인

wards_census = wards.merge(census, on='ward')
print(wards_census.head(4))

  ward  alderman         address_x        zip_x  pop_2000  pop_2010  change  address_y        zip_y
0 1     Proco "Joe" ...  2058 NORTH W...  60647  52951     56149     6%      2765 WEST SA...  60647
1 2     Brian Hopkins    1400 NORTH  ...  60622  54361     55805     3%      WM WASTE MAN...  60622
2 3     Pat Dowell       5046 SOUTH S...  60609  40385     53039     31%     17 EAST 38TH...  60653
3 4     William D. B...  435 EAST 35T...  60616  51953     54589     5%      31ST ST HARB...  60653

print(wards_census.shape)

(50, 9)

내부 조인

내부 조인 벤 다이어그램

접미사

print(wards_census.columns)

Index(['ward', 'alderman', 'address_x', 'zip_x', 'pop_2000', 'pop_2010', 'change',
       'address_y', 'zip_y'],
      dtype='object')

접미사

wards_census = wards.merge(census, on='ward', suffixes=('_ward','_cen'))
print(wards_census.head())
print(wards_census.shape)

  ward  alderman         address_ward     zip_ward  pop_2000  pop_2010  change  address_cen      zip_cen
0 1     Proco "Joe" ...  2058 NORTH W...  60647     52951     56149     6%      2765 WEST SA...  60647   
1 2     Brian Hopkins    1400 NORTH  ...  60622     54361     55805     3%      WM WASTE MAN...  60622   
2 3     Pat Dowell       5046 SOUTH S...  60609     40385     53039     31%     17 EAST 38TH...  60653   
3 4     William D. B...  435 EAST 35T...  60616     51953     54589     5%      31ST ST HARB...  60653   
4 5     Leslie A. Ha...  2325 EAST 71...  60649     55302     51455     -7%     JACKSON PARK...  60637  
(50, 9)

연습해 봅시다!

pandas로 데이터 조인하기