Scanning a hive-partitioned dataset
The team also stores cleaned-up Parquet checkouts in a hive-partitioned layout, with one directory per year (checkoutyear=2023/, checkoutyear=2024/). Scan the partitioned dataset and filter on the partition column so Polars only reads the years you actually need.
polars is loaded as pl, and the root directory is in HIVE_DIR. The partition directories are printed for you, so you can see the layout.
This exercise is part of the course
Scaling and Optimizing Data Pipelines with Polars
Exercise instructions
- Scan
HIVE_DIRusing the right argument to enable hive partitioning. - Filter the result to checkouts from 2024 onward.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
requests = pl.scan_parquet(
HIVE_DIR,
# Enable hive partitioning
____=True,
)
result = (
requests
# Filter to the 2024 partition
.filter(pl.col("checkoutyear") >= ____)
.group_by("format")
.agg(pl.col("checkouts").sum().alias("total"))
.sort("total", descending=True)
.collect()
)
print(result)