Recruiters want to know how long it takes to fill roles at each level. A post's time open is the number of days from posted_on to closed_on; posts that are still open have no closed_on.
From job_posts.csv, store the average days open per seniority, for closed posts only, rounded to 1 decimal, as a Series.
Expected answer
Store your answer in result.
Hints, the later steps and the answer come with Pro.
import pandas as pd
posts = pd.read_csv("job_posts.csv")
result = ...