json.loads() returns a string

Question

Why is json.loads() returning a string? Here's is my code:

import json

d = """{
    "reference": "123432",
    "business_date": "2019-06-18",
    "final_price": 40,
    "products": [
        {
            "quantity": 4,
            "original_price": 10,
            "final_price": 40,
        }
    ]
}"""

j = json.loads(json.dumps(d))
print(type(j))

Output:

<class 'str'>

Shouldn't it returning a json object? What change is required here?

```{ "reference": "123432", "business_date": "2019-06-18", "final_price": 40, "products": [ { "quantity": 4, "original_price": 10, "final_price": 40, } ] } ```JSON Data ```Invalid JSON: Expecting property name enclosed in double quotes: line 10 column 9 (char 215) None [Program finished]```Commenting for future readers — Subham, Mar 17 '21 at 10:23

Sebastien D · Accepted Answer · 2019-06-24T12:22:23.353

6

Two points:

You have a typo in your products key : "final_price": 40, should be "final_price": 40 (without comma)
j should be json.loads(d)

Output

dict

EDIT

Reasons why you can not have a trailing comma in a json objects are explained in this post Can you use a trailing comma in a JSON object?

Unfortunately the JSON specification does not allow a trailing comma. There are a few browsers that will allow it, but generally you need to worry about all browsers.

edited Jun 24 '19 at 12:22

answered Jun 24 '19 at 11:28

Sebastien D

4,369
4
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1

the comma will not affect the result in python. – Rahul charan Jun 24 '19 at 11:52
actually it does : `Expecting property name enclosed in double quotes: line 10 column 9 (char 215)` – Sebastien D Jun 24 '19 at 11:57
1

`d = {'a':10,}` AND `d = {'a':10}` . Both will give the same result. Python is not case sensitive. Try it on your machine – Rahul charan Jun 24 '19 at 12:03
1

and `json.loads('{"a":[10,]}')` vs `json.loads('{"a":[10]}')` ? – Sebastien D Jun 24 '19 at 12:08
1

see https://stackoverflow.com/questions/201782/can-you-use-a-trailing-comma-in-a-json-object – Sebastien D Jun 24 '19 at 12:17
1

You are correct here. I never thought about it. I have learnt something new today. – Rahul charan Jun 24 '19 at 12:18
It's a subset of a big json. I couldn't pin down that trailing comma. Removing it resolved it. Thanks! – Zid Jun 24 '19 at 12:23
How can I return a Json not dictionary? – Yamur Jan 22 '21 at 11:41

bharatk · Answer 2 · 2019-07-15T05:32:53.087

ast.literal_eval: Safely evaluate an expression node or a string containing a Python literal or container display. The string or node provided may only consist of the following Python literal structures: strings, bytes, numbers, tuples, lists, dicts, sets, booleans, None, bytes and sets. more details

import ast

d = """{
    "reference": "123432",
    "business_date": "2019-06-18",
    "final_price": 40,
    "products": [
        {
            "quantity": 4,
            "original_price": 10,
            "final_price": 40,
        }
    ]
}"""

data = ast.literal_eval(d)

print(data)
print(type(data))

O/P:

{'reference': '123432', 'business_date': '2019-06-18', 'final_price': 40, 'products': [{'quantity': 4, 'original_price': 10, 'final_price': 40}]}
<class 'dict'>

score 2 · Answer 3 · answered Jun 24 '19 at 11:57

1). The type of d AND j will remain same.

import json

d = """{
 "reference": "123432",
 "business_date": "2019-06-18",
 "final_price": 40,
 "products": [
    {
        "quantity": 4,
        "original_price": 10,
        "final_price": 40,
    }
    ]
}"""
print(type(d))

j = json.loads(json.dumps(d))
print(type(j))

2). Now Both have Dictionary type:-

import json

d = {
 "reference": "123432",
 "business_date": "2019-06-18",
 "final_price": 40,
 "products": [
    {
        "quantity": 4,
        "original_price": 10,
        "final_price": 40,
    }
    ]
}
print(type(d))

j = json.loads(json.dumps(d))
print(type(j))

This is the reason we use json format. I hope this may help you.

score 1 · Answer 4 · answered Jun 24 '19 at 11:35

1

In your code, d is supposed to be a JSON string. If it were, you wouldn't therefore need to dump it before loading it.

When I remove the string quotes, meaning that the json.dumps call is working on a dict not a string everything seems to come out fine:

import json

d = {
    "reference": "123432",
    "business_date": "2019-06-18",
    "final_price": 40,
    "products": [
        {
            "quantity": 4,
            "original_price": 10,
            "final_price": 40,
        }
    ]
}

j = json.loads(json.dumps(d))
print(type(j))

prints out

<class 'dict'>

Note, however, that trying to apply json.loads to the existing string will produce an error because JSON is less forgiving than Python, and doesn't allow dangling commas at the end of lists and dicts (see the "final_price" element definition).

answered Jun 24 '19 at 11:35

holdenweb

33,305
7
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It is a json string. But since it was not working simply with json.loads(s), I tried to dump it before loading it and it worked. But the issue was the trailing comma after 40 in 'final_price'. Removing it fixed the issue. Thanks for input. – Zid Jun 24 '19 at 12:25
1

That was my point - with the additional comma, it was no longer valid JSON, so passing it to `json.loads` errored with `json.decoder.JSONDecodeError: Expecting property name enclosed in double quotes: line 10 column 9 (char 215)`. Anyway, glad it's resolved. – holdenweb Jun 24 '19 at 12:33
1

You are right. It's not json string anymore although earlier it was. Actually its a subset of a big json string I got from json.dumps(json_obj). Editing it in notepad++ left that trailing comma. – Zid Jun 24 '19 at 13:00

json.loads() returns a string

4 Answers4