A/B Test P-Value for Time to Pickup

Problem: A/B Test P-Value for Time to Pickup Waymo ran an A/B test in San Francisco during July 2024 for a new routing algorithm intended to reduce time to pickup (TTP). You are given two Pandas DataFrames: df_users(user_id, variant), where variant identifies an assignment such as control or treatment; df_rides(ride_id, user_id, ride_date, city, time_to_pickup). Implement a function that: filters rides to city = 'SF' and dates in July 2024; joins them to experiment assignments by user_id; performs a two-sided Welch independent-samples t-test on time_to_pickup for treatment versus control; returns the p-value. Assume variant contains exactly control and treatment.