New listings don't have a review_score yet. Filling every gap with one global number would blur the differences between cities, so the team fills each gap with the median score of that listing's city.
In listings.csv, fill each missing review_score with the median score of its city, then store the average score per city, rounded to 2 decimals, as a Series.
Expected answer
Store your answer in result.
Hints, the later steps and the answer come with Pro.
import pandas as pd
listings = pd.read_csv("listings.csv")
result = ...