import json
import types

path= "R:/IT/temp/json_object.test"

test_dict = {'a':'1','b':'2','c_sub':{'sub':'item'}}
dump_file = open(path,'w')

obj = json.dumps(test_dict)
dump_file.write(obj)
dump_file.close()

load_file = open(path, 'r')
string = json.load(load_file)

print types.TypeType(string)
for a,b in string.iteritems():
    print a,b