palantir-local-dev-loop

# Palantir Local Dev Loop ## Overview Set up local development for Palantir Foundry integrations. Covers running transforms locally against sample data, mocking the Foundry API for fast iteration, and testing with pytest before pushing to Foundry. ## Prerequisites - Completed `palantir-install-auth` setup - Python 3.9+ with pip - A Foundry Code Repository cloned locally (or a standalone project) ## Instructions ### Step 1: Project Structure ``` my-foundry-project/ ├── src/myproject/ │ ├── __init__.py │ ├── pipeline.py # @transform functions │ └── utils.py # Shared logic ├── tests/ │ ├── conftest.py # Fixtures with sample DataFrames │ ├── test_pipeline.py # Transform unit tests │ └── sample_data/ # CSV/Parquet test fixtures ├── .env # FOUNDRY_HOSTNAME, FOUNDRY_TOKEN ├── requirements.txt # foundry-platform-sdk, pytest, pyspark └── pyproject.toml ``` ### Step 2: Install Local Dependencies ```bash set -euo pipefail pip install foundry-platform-sdk pyspark pytest pandas python -c "import foundry; import pyspark; print('Dependencies ready')" ``` ### Step 3: Test Transforms Locally with PySpark ```python # tests/conftest.py import pytest from pyspark.sql import SparkSession @pytest.fixture(scope="session") def spark(): return SparkSession.builder.master("local[2]").appName("test").getOrCreate() @pytest.fixture def sample_orders(spark): data = [ ("ORD-001", "alice@company.co...