Icke-personaliserade rekommendationer

Bygga rekommendationsmotorer i Python

Rob O'Callaghan

Director of Data

Icke-personaliserade betyg

Exempel på tre böcker som ofta köps tillsammans.

Hitta de mest populära artiklarna

book_df DataFrame:

Användare	Bok
User_233	The Great Gatsby
User_651	The Catcher in the Rye
User_131	The Lord of the Rings
User_965	Little Women
User_651	Fifty Shades of Grey
...	...

Hitta de mest populära artiklarna

book_df['book'].value_counts()

40 Shades of Grey                      524
Harry Potter and the Sorcerer's Stone  487
The Da Vinci Code                      455
The Twilight Saga                      401
Lord of the Rings                      278
                                     ...

Hitta de mest populära artiklarna

print(book_df.value_counts().index)

Index(['40 Shades of Grey', 'Harry Potter and the Sorcerer's Stone',
       'The Da Vinci Code', 'The Twilight Saga',
       'The Lord of the Rings'],
      dtype='object')

Hitta de mest omtyckta artiklarna

user_ratings DataFrame:

Användare	Bok	Betyg
User_233	The Great Gatsby	3.0
User_651	The Catcher in the Rye	5.0
User_131	The Lord of the Rings	3.0
User_965	Little Women	4.0
User_651	Fifty Shades of Grey	2.0
...	...	...

Hitta de mest omtyckta artiklarna

avg_rating_df = user_ratings[["book", "rating"]].groupby(['book']).mean()
avg_rating_df.head()

                                      rating
title                                      
Hamlet                                   4.1
The Da Vinci Code                       2.1
Gone with the Wind                       4.2
Fifty Shades of Grey                     1.2
Wuthering Heights                        3.9
                                          ...

Hitta de mest omtyckta artiklarna

sorted_avg_rating_df = avg_rating_df.sort_values(by="rating", ascending=False)
sorted_avg_rating_df.head()

                                      rating
title                                      
The Girl in the Fog                      5.0
Behind the Bell                          5.0
Across the River and into the Trees      5.0
The Complete McGonagall                  5.0
What Is to Be Done?                      5.0
                                          ...

Hitta de mest omtyckta artiklarna

(user_ratings['title']=='The Girl in the Fog').sum()

(user_ratings['title']=='Valley of the Dolls').sum()

(user_ratings['title']=='Across the River and into the Trees').sum()

Hitta de mest omtyckta populära artiklarna

book_frequency = user_ratings["book"].value_counts()
print(book_frequency)

40 Shades of Grey                      524
Harry Potter and the Sorcerer's Stone  487
                                       ...

frequently_reviewed_books = book_frequency[book_frequency > 100].index
print(frequently_reviewed_books)

Index([u'The Lord of the Rings', u'To Kill a Mockingbird', u'Of Mice and Men',
       u'1984', u'Hamlet'])

Hitta de mest omtyckta populära artiklarna

frequent_books_df =  user_ratings_df[user_ratings_df["book"].isin(frequently_reviewed_books)]

frequent_books_avgs = frequently_reviewed_books[["title", "rating"]].groupby('title').mean()
print(frequent_books_avgs.sort_values(by="rating", ascending=False).head())

                                      rating
title                                      
To Kill a Mockingbird                    4.7
1984.                                    4.7
Harry Potter and the Sorcerer's Stone    4.6
                                          ...

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