Left join

Joining Data with pandas

Aaren Stubberfield

Instructor

Quick review

Inner join venn diagram

Joining Data with pandas

Left join

Left join venn diagram

Joining Data with pandas

Left join

Image of two tables merged with a left join

Joining Data with pandas

New dataset

Logo of the Movie DB

Collage of movie posters

Joining Data with pandas

Movies table

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)
Joining Data with pandas

Tagline table

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)
Joining Data with pandas

Merge with 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...
Joining Data with pandas

Number of rows returned

print(movies_taglines.shape)
(4805, 5)
Joining Data with pandas

Let's practice!

Joining Data with pandas

Preparing Video For Download...