[Answer]-Parsing data to Objective-C with XML or JSON with Python / Django backend

It really depends on the data you need to represent.

If you need to represent programming language objects, JSON is probably you best choice, being more lightweight and human-readable than XML.

If you need to represent a complex data structure with its custom schema, you will probably want to give XML a shot.

That being said, Objective-C provides both XML and JSON parsers.