Let us see how to convert JSON data into a custom object in Python. Converting JSON data into a custom python object is also known as decoding or deserializing JSON data. To decode JSON data we can make use of the json.loads(), json.load() method and the object_hook parameter. The object_hook parameter is used so that, when we execute json.loads(), the return value of object_hook will be used instead of the default dict value.We can also implement custom decoders using this.
Example 1 :
# importing the module import json
from collections import namedtuple
# creating the data data = '{"name" : "Geek", "id" : 1, "location" : "Mumbai"}'
# making the object x = json.loads(data, object_hook =
lambda d : namedtuple( 'X' , d.keys())
( * d.values()))
# accessing the JSON data as an object print (x.name, x. id , x.location)
|
Output :
As we can see in the above example, the namedtuple is a class, under the collections module. It contains keys that are mapped to some values. In this case, we can access the elements using keys and indexes. We can also create a custom decoder function, in which we can convert dict into a custom Python type and pass the value to the object_hook parameter which is illustrated in the next example.
Example 2 :
# importing the module import json
from collections import namedtuple
# customDecoder function def customDecoder(geekDict):
return namedtuple( 'X' , geekDict.keys())( * geekDict.values())
# creating the data geekJsonData = '{"name" : "GeekCustomDecoder", "id" : 2, "location" : "Pune"}'
# creating the object x = json.loads(geekJsonData, object_hook = customDecoder)
# accessing the JSON data as an object print (x.name, x. id , x.location)
|
Output :
We can also use SimpleNamespace class from the types module as the container for JSON objects. Advantages of a SimpleNamespace solution over a namedtuple solution: –
- It is faster because it does not create a class for each object.
- It is shorter and simpler.
Example 3 :
# importing the module import json
try :
from types import SimpleNamespace as Namespace
except ImportError:
from argparse import Namespace
# creating the data data = '{"name" : "GeekNamespace", "id" : 3, "location" : "Bangalore"}'
# creating the object x = json.loads(data, object_hook = lambda d : Namespace( * * d))
# accessing the JSON data as an object print (x.name, x. id , x.location)
|
Output :