How to convert to a Python datetime object with JSON.loads?

Question

I have a string representation of a JSON object.

dumped_dict = '{"debug": false, "created_at": "2020-08-09T11:24:20"}' 

When I call json.loads with this object;

json.loads(dumped_dict) 

I get;

{'created_at': '2020-08-09T11:24:20', 'debug': False} 

There is nothing wrong in here. However, I want to know if there is a way to convert the above object with json.loads to something like this:

{'created_at': datetime.datetime(2020, 08, 09, 11, 24, 20), 'debug': False} 

Shortly, are we able to convert datetime strings to actual datetime.datetime objects while calling json.loads?

Answer 1

My solution so far:

>>> json_string = '{"last_updated": {"$gte": "Thu, 1 Mar 2012 10:00:49 UTC"}}' >>> dct = json.loads(json_string, object_hook=datetime_parser) >>> dct {u'last_updated': {u'$gte': datetime.datetime(2012, 3, 1, 10, 0, 49)}}   def datetime_parser(dct):     for k, v in dct.items():         if isinstance(v, basestring) and re.search("\ UTC", v):             try:                 dct[k] = datetime.datetime.strptime(v, DATE_FORMAT)             except:                 pass     return dct 

For further reference on the use of object_hook: JSON encoder and decoder

In my case the json string is coming from a GET request to my REST API. This solution allows me to 'get the date right' transparently, without forcing clients and users into hardcoding prefixes like __date__ into the JSON, as long as the input string conforms to DATE_FORMAT which is:

DATE_FORMAT = '%a, %d %b %Y %H:%M:%S UTC' 

The regex pattern should probably be further refined

PS: in case you are wondering, the json_string is a MongoDB/PyMongo query.

Answer 2

You need to pass an object_hook. From the documentation:

object_hook is an optional function that will be called with the result of any object literal decoded (a dict). The return value of object_hook will be used instead of the dict.

Like this:

import datetime import json  def date_hook(json_dict):     for (key, value) in json_dict.items():         try:             json_dict[key] = datetime.datetime.strptime(value, "%Y-%m-%dT%H:%M:%S")         except:             pass     return json_dict  dumped_dict = '{"debug": false, "created_at": "2020-08-09T11:24:20"}' loaded_dict = json.loads(dumped_dict, object_hook=date_hook) 

If you also want to handle timezones you'll have to use dateutil instead of strptime.