Left join

Joining Data with pandas

Aaren Stubberfield

Instructor

Rychlé opakování

Vennův diagram inner join

Left join

Vennův diagram left join

Left join

Dvě tabulky spojené pomocí left join

Nová datová sada

Logo The Movie DB

Koláž filmových plakátů

Tabulka movies

movies = pd.read_csv('tmdb_movies.csv')
print(movies.head())
print(movies.shape)

  id     original_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  
(4803, 4)

Tabulka taglines

taglines = pd.read_csv('tmdb_taglines.csv')
print(taglines.head())
print(taglines.shape)

  id      tagline
0 19995   Enter the World of Pandora.
1 285     At the end of the world, the adventure begins.
2 206647  A Plan No One Escapes
3 49026   The Legend Ends
4 49529   Lost in our world, found in another.
(3955, 2)

Merge s left join

movies_taglines = movies.merge(taglines, on='id', how='left')
print(movies_taglines.head())

  id     original_title   popularity       release_date  tagline        
0 257    Oliver Twist     20.415572        2005-09-23    NaN            
1 14290  Better Luck ...  3.877036         2002-01-12    Never undere...
2 38365  Grown Ups        38.864027        2010-06-24    Boys will be...
3 9672   Infamous         3.6808959999...  2006-11-16    There's more...
4 12819  Alpha and Omega  12.300789        2010-09-17    A Pawsome 3D...

Počet vrácených řádků

print(movies_taglines.shape)

(4805, 5)

Pojďme si procvičit!

Joining Data with pandas