find and replace element in file using python 3.7 - python-3.x

Question

I am learning python and in the code below I am trying to replace all values where "id": null, with "id": na,...
there may not always be an id in every block. If c does not have that pattern in it then it is skipped. Thank you :)
file
{
"objects": [
{
"version": "1",
"id": null,
"date": 1,
...,
},
{
"version": "1",
"id": 1xx1,
"date": 1,
...,
},
desired
{
"objects": [
{
"version": "1",
"id": na,
"date": 1,
...,
},
{
"version": "1",
"id": 1xx1,
"date": 1,
...,
},
python3
import json
with open('file.json',encoding='utf8') as in_file:
data = json.load(in_file)
for c in data['objects']: # read all elements in object into c
if c = "\"id\""\: null,: # check to see if element in c is "id": null,
data[c] = "\"id\""\: na, # replace c with

Answer 1

You want to use None in python for a NoneType not null i.e. if not obj['id']: but None is falsy so you can just use if not
import json
with open('file.json', encoding='utf8') as in_file:
data = json.load(in_file)
for obj in data['objects']:
if not obj['id']:
obj['id'] = 'na'
print(data)
"id": an is invalid as Json and in a Python dictionary I think you want to either initialise an as a variable or use a string "id": "an"
Or more concisely use comprehensions:
import json
with open('file.json', encoding='utf8') as in_file:
print(json.dumps({'objects': [{k: 'na' if k == 'id' and not v else v for k, v in entry.items()} for entry in json.load(in_file)['objects']]}))
As #Mohamed Fathallah suggests use json.dump() to write the data to a file or json.dumps() to display it as a json formatted string.

Answer 2

The Error is in following code
if c = "\"id\""\: null,: # check to see if element in c is "id": null,
data[c] = "\"id\""\: na, # replace c with
As #Dan-Dev mentioned, the null in c#, c++, etc. is None in Python. You can use this code and read my code as side information to understand more.
import json
with open('file.json', 'r') as file:
data = json.load(file)
for obj in data['objects']:
if obj.get('id') is None:
obj['id'] = 'na'
# if you want to write back
with open('data.json', 'w') as file:
json.dump(data, file, indent=2)