Typeerror: object of type textiowrapper is not json serializable

The typeerror: object of type textiowrapper is not json serializable is an error message in Python.

This article will help you better understand this error.

Remember that the first step in fixing an error is understanding it.

So, without further delay, let us begin understanding this error.

What is typeerror: object of type textiowrapper is not json serializable?

As cited above, the typeerror: object of type textiowrapper is not json serializable is an error message that occurs in Python.

The error mentioned occurs when we attempt to serialize the object TextIOWrapper to JSON.

What is TextIOWrapper?

The TextIOWrapper in Python is a class.

It is used for reading and writing text files.

What is JSON serialization?

JSON (JavaScript Object Notation) serialization is a process that converts Python objects into JSON-formatted text.

It can only be used with certain data types.

Example data types:

✅ Strings, integers, lists, and dictionaries

The discussion above explains why the error arises when we attempt to serialize the object TextIOWrapper to JSON.

Here is a sample code that causes this error:

import json

with open('sample.txt', 'r') as f:
    text = f

data = json.dumps(text)
print(data)

Error:

Traceback (most recent call last):
  File "C:\Users\path\PyProjects\sProject\main.py", line 6, in <module>
    data = json.dumps(text)
           ^^^^^^^^^^^^^^^^
  File "C:\Users\path\AppData\Local\Programs\Python\Python311\Lib\json\__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\path\AppData\Local\Programs\Python\Python311\Lib\json\encoder.py", line 200, in encode
    chunks = self.iterencode(o, _one_shot=True)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\path\AppData\Local\Programs\Python\Python311\Lib\json\encoder.py", line 258, in iterencode
    return _iterencode(o, 0)
           ^^^^^^^^^^^^^^^^^
  File "C:\Users\path\AppData\Local\Programs\Python\Python311\Lib\json\encoder.py", line 180, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type TextIOWrapper is not JSON serializable

Now, let us move on to our solution.

Typeerror: object of type textiowrapper is not json serializable – SOLUTION

Complete code:

import json

with open('sample.txt', 'r') as f:
    text = f.read()

data = json.dumps(text)
print(data)

Output:

"Hi, IT source codes! Happy coding!"

Alternative solutions

Aside from the solution provided above, you can also use these solutions:

✅ Use the json.dump() method.

Example code:

import json

with open('sample.txt', 'r') as f:
    text = f.read()
    with open('output.json', 'w') as json_file:
        json.dump(text, json_file)

✅ Convert the object TextIOWraper into a data type that is JSON-serializable.

Example code:

import json

with open('sample.txt', 'r') as f:
    text = f.readlines()
    data_list = [line.strip() for line in text]
    json_data = json.dumps({'text': data_list})
print(json_data)

Output:

{"text": ["Hi, IT source codes! Happy coding!"]}

You might also want to see these related articles:

• Typeerror: object of type datetime is not json serializable
• Typeerror: object of type ndarray is not json serializable
• Typeerror: object of type int64 is not json serializable
• Typeerror object of type float32 is not json serializable

Tips to avoid getting type errors

The following are some tips to avoid getting type errors in Python.

• Avoid using the built-in data types in Python in the wrong way.
• Always check or confirm the types of your variables.
• Be clear and concise when writing code.
• Handle the error by using try-except blocks.
• Use the built-in functions of Python if needed.

FAQs

Python TypeError debugging checklist

• Read the full traceback. The bottom line is the error type + message. The line above shows the exact code that triggered it.
• Print types. Insert print(type(x), type(y)) before the error line to see what Python actually has.
• Use isinstance. Guard code with if isinstance(x, expected_type):.
• Type hints + mypy. Adding x: int lets mypy catch mismatches before you run the code.
• Break into a debugger. Insert breakpoint() before the failing line and inspect variables live.

Common root causes across all TypeError variants

• Silent None returns. A function that should have returned a value returned None instead.
• Mixing types across function boundaries. Legacy code passing str where int is expected (or vice versa).
• Shadowed builtins. Local variable named list, dict, set overriding the built-in.
• Optional[T] not handled. Callers not accounting for the None case.
• Third-party library API drift. New version renamed a kwarg or changed a return type.

Modern tooling to prevent TypeError

• Type hints (PEP 484+). Optional[X], Union[X,Y], List[T] make expected types explicit.
• mypy or Pyright. Runs your codebase through a type checker before you run it.
• Ruff. Fast linter that catches many TypeError-adjacent bugs.
• pydantic v2. Runtime validation with the same syntax as static types.
• pytest fixtures. Test each function with edge-case inputs to catch TypeError paths early.

Conclusion

In conclusion, the typeerror: object of type textiowrapper is not json serializable is an error message that occurs in Python.

You can solve this error using a JSON serializable object instead of the TextIOWrapper object for the JSON serialization method.

By following the guide above, you will surely solve this error quickly.

That is all for this tutorial, IT source coders!

We hope you have learned a lot from this. Have fun coding!

Thank you for reading! 😊

Elijah Galero

Programmer & Technical Writer at PIES IT Solution

Elijah Galero is a programmer and writer at PIES IT Solution, author of 175+ tutorials at itsourcecode.com. Specializes in Python error debugging (AttributeError, TypeError, ModuleNotFoundError), Python programming tutorials, and Microsoft Excel how-to guides for BSIT students and productivity learners.

Expertise: Python · Python Errors · Python AttributeError · Python TypeError · ModuleNotFoundError · MS Excel · MS PowerPoint
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