Question

PYTHON 3

Netflix stores a database that we can represent as a dict, whose keys are movie titles like 'Pscyho' (str); associated with each title is a set of 2-tuples. Each 2-tuple specifies the name of a reviewer (str) followed by a review score (int: a number 0-5); for example ('Alice', 5). A simple/small database can look like

  {'Psycho':  {('Bob', 5),  ('Carrie', 5), ('Alan', 1), ('Diane', 1)},
   'Amadeus': {('Carrie', 3), ('Diane', 3), ('Bob', 3)},
   'Up':      {('Alan', 2), ('Diane', 5)},
   'Jaws':    {('Carrie', 2), ('Alan', 5)} }

Define the score_dict function to return a dict whose keys are the scores, where each reviewer is associated with a set of 2-tuples (movie names and their reviewer). If db is bound to the database above, calling score_dict (db) returns the dict

{1: {('Psycho', 'Diane'), ('Psycho', 'Alan')},
2: {('Jaws', 'Carrie'), ('Up', 'Alan')},
3: {('Amadeus', 'Diane'), ('Amadeus', 'Bob'), ('Amadeus', 'Carrie')},
5: {('Jaws', 'Alan'), ('Up', 'Diane'), ('Psycho', 'Carrie'), ('Psycho', 'Bob')} }

Answer 1

Solution:

from collections import defaultdict
db_data = {'Psycho':  {('Bob', 5),  ('Carrie', 5), ('Alan', 1), ('Diane', 1)},
           'Amadeus': {('Carrie', 3), ('Diane', 3), ('Bob', 3)},
           'Up':      {('Alan', 2), ('Diane', 5)},
           'Jaws':    {('Carrie', 2), ('Alan', 5)}}

def score_dict():
    # Creating score of type defaultdict to store set
    score = defaultdict(set)
    # Iterating over the db data and extracting key and values
    for key, values in db_data.items():
        movie_title = key # storing key into movie_title
        # Iterating over the values
        for value in values:
            # Storing 1st and 2nd tuple value into meaningful names
            reviewer_name = value[0]
            reviewer_score = value[1]
            # Adding tuple of movie title and reviewer name based on the scores
            score[reviewer_score].add((movie_title, reviewer_name))
    # Returning the score
    return score

# Calling and printing the method output
print(score_dict())

Sample Run:

defaultdict(<class 'set'>, {1: {('Psycho', 'Alan'), ('Psycho', 'Diane')}, 2: {('Up', 'Alan'), ('Jaws', 'Carrie')}, 3: {('Amadeus', 'Bob'), ('Amadeus', 'Carrie'), ('Amadeus', 'Diane')}, 5: {('Psycho', 'Bob'), ('Psycho', 'Carrie'), ('Jaws', 'Alan'), ('Up', 'Diane')}})

Sample Image of code and run:

Note: Just copy paste the code it should work fine, I have attached the image for the reference. If you have any doubt then please do let me know. Thanks