nested dictionary python

Question

How do I create a nested dictionary in python So, I want the data be in this form..

{Category_id: {Product_id:... productInstance},{prod_id_1: this instance}         


        

Answer 1

I think this is closer to what you want:

fin = readFile(db)
categoryDict = defaultdict(dict)     # automatically create a subdict
for line in fin:
    itemDict = {}                    # a new innermost dict for every item
    itemInstance = setItemInstances(line)
    itemDict[itemInstance._product_id] = itemInstance
    categoryDict[itemInstance._category_id] = itemDict