JSON Validation

Overview

We noted that our mypy type hint doesn’t really guarantee the JSON document is—in any way—what we expected. There is a package in the Python Package Index that can be used for this. The jsonschema package lets us provide a specification for a JSON document, and then confirm whether or not the document meets the specification.

The JSON Schema validation is a runtime check, unlike the mypy type hint. This means using validation will make our program slower. It can also help to diagnose subtly incorrect JSON documents. For details, visit https://json-schema.org. This is evolving toward standardization, and there are several versions of compliance checking available.

We’ll focus on newline-delimited ...