Python Algorithm to flattening JSON

Algorithm to flatten the deep JSON structure:

def flat(root, **args):
    d = {}
    for k, v in args.iteritems():
        if type(v) == dict:
            d.update(flat((k if root == None else '{}.{}'.format(root,k)),**v))
        elif type(v) == list:
            for idx, item in enumerate(v):
                d.update(flat('{}.{}'.format(k if root == None else '{}.{}'.format(root,k),idx), **item))
        else:
            if root == None:
                d['{}'.format(k)] = v
            else:
                d['{}.{}'.format(root,k)] = v
            #print ('key: {}, val: {}'.format(k,v))
    return d

for example, if you flatten the following JSON structure:

tt ={'name':{'firstName':'Tom', 'lastName':'Hanks'},
    'orderlineitems':[{'rice':{'qty':2,'price':10}},{'bread':{'qty':1,'price':2}}],
    'age':20, 'location':{'country':'AU','state_loc':{'state':'NSW', 'postal':2112}}}

flat(None,**tt)

The result is as follows:

{'age': 20,
 'location.country': 'AU',
 'location.state_loc.postal': 2112,
 'location.state_loc.state': 'NSW',
 'name.firstName': 'Tom',
 'name.lastName': 'Hanks',
 'orderlineitems.0.rice.price': 10,
 'orderlineitems.0.rice.qty': 2,
 'orderlineitems.1.bread.price': 2,
 'orderlineitems.1.bread.qty': 1}