Calculating cumulative rentals
Rolling sums smooth short-term noise, but sometimes you need the running total from the very start. Cumulative sums track how usage builds up over time, useful for capacity planning and monthly reporting.
polars is loaded as pl. The DataFrame bikes is available with columns time, rentals, and temp.
Questo esercizio fa parte del corso
Data Transformation with Polars
Istruzioni dell'esercizio
- Add a column
cumulative_rentalswith the cumulative sum ofrentals.
Esercizio pratico interattivo
Prova a risolvere questo esercizio completando il codice di esempio.
# Add a cumulative sum of rentals
bikes.with_columns(
pl.col("rentals").____().alias("____")
)