ช่วงเวลาระหว่างการเดินทางแต่ละครั้งนานแค่ไหน?

# Shift the index of the end date up one; now subract it from the start date
rides['Time since'] = rides['Start date'] - (rides[____].shift(1))

# Move from a timedelta to a number of seconds, which is easier to work with
rides['Time since'] = rides['Time since'].____

# Resample to the month
monthly = rides.____('____', on = 'Start date')

# Print the average hours between rides each month
print(monthly['Time since'].____/(60*60))