The CSV From Hell

Board deck by 4pm — Jennifer needs a chart

Jennifer (VP Marketing): Q3 campaign CSV attached. Just make a conversion-rate-by-channel chart for the board deck.

Analytics Lead: Mixed date formats, $ and € in the same column, impressions as 1.2M, nulls as N/A / null / - / blank, and column names with trailing spaces. Clean it first.

Your task

Implement load_and_clean() and analyze() in `clean_and_analyze.py`. Do not edit the CSV by hand. CI validates the cleaned DataFrame and ROAS summary.

Book: read_csv(), dropna(), fillna() · Prod: 6 real-world data quality issues in one marketing dump.