Menu
I am new to Python and I am playing with JSON data. I would like to dynamically build a JSON object by adding some key-value to an existing JSON object.
I tried the following but I get TypeError: 'str' object does not support item assignment:
import json
json_data = json.dumps({})
json_data["key"] = "value"
print 'JSON: ', json_data
740
A dynamic JSON file will be created to store the array of JSON objects. Consider, we have a database named gfg, a table named userdata. Now, here is the PHP code to fetch data from database and store them into JSON file named gfgfuserdetails. json by converting them into an array of JSON objects.
In Python, you can create JSON string by simply assigning a valid JSON string literal to a variable, or convert a Python Object to JSON string using json. loads() function.
To convert string to json in Python, use the json. loads() function. The json. loads() is a built-in Python function that accepts a valid json string and returns a dictionary to access all elements.
This is one of most common scenarios and you’ll see two ways of creating JSON array dynamically. The first method will use for loop for creating JSON array from an input array. The second method will make use of the JavaScript reduce method to create dynamic JSON array. How JavaScript Variables are Stored in Memory? What Does ...
"JSON" stands for "JavaScript Object Notation" - it's just a specification for representing some data in a string that explicitly mimics JavaScript object (and array, string, number and boolean) literals. You're trying to build up a JavaScript object dynamically - so the word you're looking for is "object".
json.dumps take a dictionary as input and returns a string as output. If you need to convert JSON data into a python object, it can do so with Python3, in one line without additional installations, using SimpleNamespace and object_hook:
First, I think you're calling it the wrong thing. "JSON" stands for "JavaScript Object Notation" - it's just a specification for representing some data in a string that explicitly mimics JavaScript object (and array, string, number and boolean) literals.
You build the object before encoding it to a JSON string:
import json
data = {}
data['key'] = 'value'
json_data = json.dumps(data)
JSON is a serialization format, textual data representing a structure. It is not, itself, that structure.
129
You can create the Python dictionary and serialize it to JSON in one line and it's not even ugly.
my_json_string = json.dumps({'key1': val1, 'key2': val2})
There is already a solution provided which allows building a dictionary, (or nested dictionary for more complex data), but if you wish to build an object, then perhaps try 'ObjDict'. This gives much more control over the json to be created, for example retaining order, and allows building as an object which may be a preferred representation of your concept.
pip install objdict first.
from objdict import ObjDict
data = ObjDict()
data.key = 'value'
json_data = data.dumps()
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
