README.md

dlt-ingestion-poc

This is a project for experimentation using dlt for data ingestion in an ETL pipeline. It uses a file of NZ Census data (comprised of 17 cols x 35.6m records) in Parquet format as the source and applies a custom cleaning function to the data before writing it back to the filesystem.

The project is structured to allow for easy modification and testing of different data ingestion and transformation strategies.

Features

• Ingests census data from Parquet files located in the files/input directory.
• Cleans the ingested data using a custom cleaning function (helpers.generic.clean_data).
• Writes the cleaned data back to the filesystem (configured via dlt.destinations.filesystem).
• Exports the inferred schema to files/schemas/export.
• Uses dlt for pipeline orchestration and data loading.
• Uses pyarrow for efficient data handling.

Setup

This project uses uv for dependency management.

1. Install uv: If you don't have uv installed, follow the instructions here.
2. Create a virtual environment:

   uv venv

3. Activate the virtual environment:
   • macOS/Linux: source .venv/bin/activate
   • Windows: .venv\Scripts\activate
4. Install dependencies:

   uv sync

   This installs the project in editable mode along with development dependencies.

Usage

To run the main data ingestion pipeline:

python census_pipeline.py

The pipeline will:

1. Read Parquet files from files/input/.
2. Apply the census_clean transformer.
3. Write the cleaned data (in Parquet format) to the destination configured in the pipeline (defaulting to a local filesystem location managed by dlt).
4. Log progress to the console.