Practice: Add metadata to taxi_zones_file

To practice what you’ve learned, add the record counts to the metadata for taxi_zones_file.

Check your work

The metadata you built should look similar to the code contained in the View answer toggle. Click to open it.

import dagster as dg


@dg.asset(
    group_name="raw_files",
)
def taxi_zones_file() -> dg.MaterializeResult:
    """
      The raw CSV file for the taxi zones dataset. Sourced from the NYC Open Data portal.
    """
    raw_taxi_zones = requests.get(
        "https://community-engineering-artifacts.s3.us-west-2.amazonaws.com/dagster-university/data/taxi_zones.csv"
    )

    with open(constants.TAXI_ZONES_FILE_PATH, "wb") as output_file:
        output_file.write(raw_taxi_zones.content)
    num_rows = len(pd.read_csv(constants.TAXI_ZONES_FILE_PATH))

    return dg.MaterializeResult(
        metadata={
            'Number of records': dg.MetadataValue.int(num_rows)
        }
    )