parse nested json data to dataframe in PYTHON in SPEEDY WAY

I have cargo flights data in JSON format. A flight contains loose items and some containers containing items. I would like to flatten these in a pandas dataFrame. Really what I care about is the bottem level in the treeI.e the package, link it to it's container (parent) and to its flight(grand parent). Nesting in these files is sometimes on 5 levels mixing dictionnaries and list. a basic case is here: Sample JSON is here: [login to view URL] Because speed matters, this can be tedious walking through the tree with for loops mixed with ifs to check if a particular parent (grand parent) actually had items inside. I want a json to dataframe conversion in Python. I have tested several methods, I get the output but I run 20 minutes to extract 150K items that is ridiculously slow. I am no expert in JSON, can you think of a faster way to parse and convert?