Learn laterite — start here

A linear, five-step tour of the library: install it, read an AGS4 file into typed frames, validate against the numbered rules, query with the builder or raw SQL, and produce byte-faithful AGS4 back out. Work through them in order — each page ends with a Next → to the following step.

1. Install — pip install laterite, the optional extras, and the lat CLI in one line.
2. Read — read() a path, text, or bytes; AGS types arrive as polars dtypes (every column is born typed).
3. Validate — run the numbered-rules engine and read the Report of findings.
4. Query — fan out a group with .at(), chain the lazy AgsQuery builder, or drop to .sql() over DuckDB.
5. Produce — build_ags4() from frames or a typed PROJ graph into a BuildResult you can .save.

Tip

In a hurry? The cheatsheet is the whole API on one page, and the cookbook has task-shaped recipes.

Next → Install