Json Data Handling

This covers the JSON fundamentals you actually need: parsing, serialization, file I/O, and pretty printing in both Python and JavaScript. It goes beyond basics with custom encoders for datetime objects, circular reference handling, and streaming large files with ijson instead of loading everything into memory. The deep merge and safe nested access patterns are genuinely useful for real API work. What I appreciate is the direct comparison between Python's json module and JavaScript's JSON object, plus the jsonschema validation example that saves you from writing manual checks. The streaming section is brief but points you in the right direction when you hit that 500MB JSON file.