ArticleViews_Pandas.py

# Write a solution to find all the authors that viewed at least one of their own articles.
# Return the result table sorted by id in ascending order.

import pandas as pd

def article_views(views): 
    df = views[views['author_id'] == views['viewer_id']]
    df = df.rename(columns={"author_id": "id"})
    return df[['id']].drop_duplicates().sort_values(by=['id'])

# schema 
data = [[1, 3, 5, '2019-08-01'], [1, 3, 6, '2019-08-02'], [2, 7, 7, '2019-08-01'], [2, 7, 6, '2019-08-02'], [4, 7, 1, '2019-07-22'], [3, 4, 4, '2019-07-21'], [3, 4, 4, '2019-07-21']]
Views = pd.DataFrame(data, columns=['article_id', 'author_id', 'viewer_id', 'view_date']).astype({'article_id':'Int64', 'author_id':'Int64', 'viewer_id':'Int64', 'view_date':'datetime64[ns]'})
print(article_views(Views))