JSON conversion: Built-in functions to convert a string in JSON format to a python object

 

Often web services, files or any other data exchange mechanism utilizes the JSON format as a standard to shared data between different processes. In this context, it is important to a programming language to provide functions to parse these JSON strings to a native object, enabling the data processing in a more feasible way then the string processing.

For python programming language there is a module name json, which contains a method to load a JSON string, but it needs an additional parameter that is the “hook function”, a function to handle how each object will de translated to object.

import json #https://docs.python.org/3/library/json.html
from types import SimpleNamespace #https://docs.python.org/3/library/types.html

print("### JSON to object example with multilevel objects ####")
data = '{"name": "Ramza Beoulve", "details": {"firstName": "Ranza", "lastName": "Beoulve"}}'

# Parse JSON into an object with attributes corresponding to its keys.
#SimpleNamespace: function that creates dynamically names for object properties
obj = json.loads(data, object_hook = lambda obj: SimpleNamespace( **obj )) # ** spread operator
print("Name:", obj.name)
print("details.firstName" , obj.details.firstName, "details.lastName", obj.details.lastName)

 

This hook function is defined in the example above using the lambda syntax. It is basically a function that receives as input an object and returns the new produced object. For performing this processing we utilize the spread operator (**) which basically clone the object properties in a new object, and then the SimpleNamespace function, which is able to based on original property names create new properties in the produced object. At the end the json.loads function returns new objects that contains all properties that are on JSON string, even when it is another objects (multi level) or arrays (several objects).

 

The complete code with more examples is available to be downloaded here:

https://github.com/rafaelqg/code/blob/main/map_reduce_reduce_example.py

 

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