import pandas as pd

left_df = pd.DataFrame()
right_df = pd.DataFrame()
left_df["title"] = ["The Avengers", "Avengers: Age of Ultron", "Avengers: Infinity War", "Avengers: Endgame"]
left_df["release_year"] = [2012, 2015, 2018, 2019]
right_df["title"] = ["Avengers: Infinity War", "Avengers: Endgame", "The Avengers", "Avengers: Age of Ultron"]
right_df["rating"] = [8.5, 8.6, 8.5, 7.3]
left_df = left_df.set_index("title")
right_df = right_df.set_index("title")
left_df
right_df
left_df.join(right_df)