[New-bugs-announce] [issue38414] Ordering a nested dictionary in python with json format

[Umar Asghar]

New submission from Umar Asghar <mrumarasghar at gmail.com>:

Python does not preserve ordering in JSON format. I have tested it out but it's not working. Here is my code.

# Python3 code to demonstrate 
# Sort nested dictionary by key 
# using OrderedDict() + sorted() 
from collections import OrderedDict 
from operator import getitem 
import json

# initializing dictionary 
test_dict = {'Nikhil' : { 'roll' : 24, 'marks' : 17}, 
            'Akshat' : {'roll' : 54, 'marks' : 12}, 
            'Akash' : { 'roll' : 12, 'marks' : 15}} 

# printing original dict 
print("The original dictionary : " + str(test_dict)) 

# using OrderedDict() + sorted() 
# Sort nested dictionary by key 
res = OrderedDict(sorted(test_dict.items(), 
    key = lambda x: getitem(x[1], 'marks'))) 

print("The sorted dictionary by marks is : " + str(res))
# Output
# The sorted dictionary by marks is : OrderedDict([('Akshat', {'marks': 12, 'roll': 54}), ('Akash', {'marks': 15, 'roll': 12}), ('Nikhil', {'marks': 17, 'roll': 24})])

res = json.dumps(res)

# print result 
print("The sorted dictionary by marks is : (json)")
print(json.loads(res)) 
# Output
# The sorted dictionary by marks is : 
# {'Akash': {'marks': 15, 'roll': 12}, 'Akshat': {'marks': 12, 'roll': 54}, 'Nikhil': {'marks': 17, 'roll': 24}}
Does anyone suggest any solution for it?

It's different than a simple dictionary. It only targets the nested dictionary ordering. Please don't mark it a duplication of simple dictionary ordering with JSON. thanks

----------
messages: 354228
nosy: Umar Asghar
priority: normal
severity: normal
status: open
title: Ordering a nested dictionary in python with json format

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue38414>
_______________________________________