其他連接

使用 pandas 進行資料表連接

Aaren Stubberfield

Instructor

Right join（右連接）

Right join venn diagram

Right join（右連接）

Image of two tables merged with a right join

檢視資料

movie_to_genres = pd.read_csv('tmdb_movie_to_genres.csv')
tv_genre = movie_to_genres[movie_to_genres['genre'] == 'TV Movie']
print(tv_genre)

       movie_id  genre
4998   10947     TV Movie
5994   13187     TV Movie
7443   22488     TV Movie
10061  78814     TV Movie
10790  153397    TV Movie
10835  158150    TV Movie
11096  205321    TV Movie
11282  231617    TV Movie

篩選資料

m = movie_to_genres['genre'] == 'TV Movie'
tv_genre = movie_to_genres[m]
print(tv_genre)

       movie_id  genre
4998   10947     TV Movie
5994   13187     TV Movie
7443   22488     TV Movie
10061  78814     TV Movie
10790  153397    TV Movie
10835  158150    TV Movie
11096  205321    TV Movie
11282  231617    TV Movie

要合併的資料

  id     title            popularity       release_date
0 257    Oliver Twist     20.415572        2005-09-23  
1 14290  Better Luck ...  3.877036         2002-01-12  
2 38365  Grown Ups        38.864027        2010-06-24  
3 9672   Infamous         3.6808959999...  2006-11-16  
4 12819  Alpha and Omega  12.300789        2010-09-17

       movie_id  genre
4998   10947     TV Movie
5994   13187     TV Movie
7443   22488     TV Movie
10061  78814     TV Movie
10790  153397    TV Movie

使用右連接合併

tv_movies = movies.merge(tv_genre, how='right', 
                         left_on='id', right_on='movie_id')
print(tv_movies.head())

  id      title            popularity  release_date  movie_id  genre   
0 153397  Restless         0.812776    2012-12-07    153397    TV Movie
1 10947   High School ...  16.536374   2006-01-20    10947     TV Movie
2 231617  Signed, Seal...  1.444476    2013-10-13    231617    TV Movie
3 78814   We Have Your...  0.102003    2011-11-12    78814     TV Movie
4 158150  How to Fall ...  1.923514    2012-07-21    158150    TV Movie

Outer join（外連接）

Full outer join venn diagram

Outer join（外連接）

Image of two tables merged with a right join

外連接用到的資料集

m = movie_to_genres['genre'] == 'Family'
family = movie_to_genres[m].head(3)

  movie_id  genre 
0 12        Family
1 35        Family
2 105       Family

m = movie_to_genres['genre'] == 'Comedy'
comedy = movie_to_genres[m].head(3)

  movie_id  genre 
0 5         Comedy
1 13        Comedy
2 35        Comedy

使用外連接合併

family_comedy = family.merge(comedy, on='movie_id', how='outer', 
                             suffixes=('_fam', '_com'))
print(family_comedy)

  movie_id  genre_fam  genre_com
0 12        Family     NaN      
1 35        Family     Comedy   
2 105       Family     NaN      
3 5         NaN        Comedy   
4 13        NaN        Comedy

一起來練習吧！

使用 pandas 進行資料表連接