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.
Latihan ini merupakan bagian dari kursus
Data Transformation with Polars
Instruksi latihan
- Add a column
cumulative_rentalswith the cumulative sum ofrentals.
Latihan interaktif langsung praktik
Cobalah latihan ini dengan melengkapi kode contoh ini.
# Add a cumulative sum of rentals
bikes.with_columns(
pl.col("rentals").____().alias("____")
)