topic Re: "Help with Parsing JSON String into Python List – Getting NoneType Error" in Workato Pros Discussion Board

"Help with Parsing JSON String into Python List – Getting NoneType Error"

Patel0786 — Tue, 28 Jan 2025 07:33:54 GMT

Hi everyone, I'm working with JSON data in Python, and I need help with converting a string representation of a JSON array into a Python list. Specifically, I'm trying to parse the following input:

'[{"name": "Alice", "age": 30}, {"name": "Bob", "age": 25}]'

and expected output -

[{'name': 'Alice', 'age': 30}, {'name': 'Bob', 'age': 25}]

When I run this, I get the error: "TypeError: the JSON object must be str, bytes or bytearray, not NoneType". What could be causing this, and how can I fix it?

Any help would be appreciated!

Re: "Help with Parsing JSON String into Python List – Getting NoneType Error"

shivakumara — Tue, 28 Jan 2025 15:00:09 GMT

Hi @Patel0786 ,

Python interprets this as a list of dictionaries because single quotes are valid for dictionary keys/values in Python.

This behavior is Python's native way of understanding data formats, and Workato's Python component doesn't add any special handling.

Best Practices:
1. Use double quotes for JSON keys and values when handling string representations of JSON.
2. Use json.dumps() to serialize your Python objects into valid JSON strings when needed.
3. Test your input in a Python interpreter to confirm how it’s parsed before using it in Workato.

Here is the syntax you have to use ( Sample screenshot)

Thanks and Regards,
Shivakumar K A

Re: "Help with Parsing JSON String into Python List – Getting NoneType Error"

Patel0786 — Thu, 30 Jan 2025 07:34:43 GMT

still getting same error

Re: "Help with Parsing JSON String into Python List – Getting NoneType Error"

shivakumara — Thu, 30 Jan 2025 12:03:38 GMT

Hi @Patel0786 ,
In the 4th line please pass the output of 3rd line ( i.e. string_data). Please try and let me know.

Thanks and Regards,
Shivakumara K