JavaScript Object Notation (JSON) is an open-standard file format, and data interchange format that employs text humans can read to store and transport data objects made up of arrays and attribute-value pairs (or other serializable values). “TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper” is a common error that many programmers encounter. It happens in many ways. What is the cause of it and how to solve this problem. Read on this article.

When Do You Get “TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper” Error?

You may encounter the error “TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper” when you run the following program:

import json

file_name = 'demo.json'
with open(file_name, 'r', encoding='utf-8') as f:
    sample_data = json.loads(f)

TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper

How To Fix “TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper” Error?

Option 1: Utilize the json.loads()

The simplest way for you to solve the error “TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper” is utilizing the json.loads().

You can use the json.load() function to deserialize a file to a Python object instead of just passing a file object to the json.loads() method. Look at the following example:

import json

file_name = 'demo.json'

with open(file_name, 'r', encoding='utf-8') as f:
    sample_data = json.load(f)
   
    print(sample_data)
    print(type(sample_data))

Output:

{'name': 'John', 'age': 36, 'nationality': 'American'}
<class 'dict'>

The aforementioned code snippet implies that you have a file named demo.json in the same directory.

While a JSON string is deserialized to a Python object using the json.load function, a file is deserialized to an object using the json.loads method.

{"name":"John", "age":36, "nationality":"American"}

Option 2: Call the read()

Calling the read() function on the File object, which returns a string containing the JSON data, will fix this error. Let’s examine the updated code:

import json

file_name = 'index.json'

with open('index.json', 'r') as f:
   
    # Call read method to get JSON string
    json_str = f.read()
    print(json_str)
    print(type(json_str))
   
    # Pass JSON string to loads() method
    example_data = json.loads(json_str)

# Print the result
print(example_data)
print(type(example_data))

You must now divide the procedure into smaller sections in order to understand how you build each object. Let’s execute the code to see what happens:

[
{"Python":1991},
{"JavaScript":1995},
{"Ruby":1995},
{"C++":1983},
{"Pascal":1970}
]

<class 'str'>
[{'Python': 1991}, {'JavaScript': 1995}, {'Ruby': 1995}, {'C++': 1983}, {'Pascal': 1970}]
<class 'list'>

A string representing the JSON file’s contents is the first object with the variable name string. The json.loads() method is then invoked with this object, and it returns a Python object, namely a list of key-value pairs for each of the five particles.

Option 3: Utilize type()

To solve the problem, let’s utilize the type() class that is built into variables if you are unsure about the type of object they store. For example:

exp_dict = {'name': 'John', 'age': 36, 'nationality': 'American'}
print(type(exp_dict)) # <class 'dict'>
print(isinstance(exp_dict, dict)) # True

exp_string = 'TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper'
print(type(exp_string)) # <class 'str'>
print(isinstance(exp_string, str)) # True

The type of an object is returned by the type class.

In the case the being passed in object is a subclass of the class or an instance, the isinstance function returns True.

Conclusion

We hope that you will enjoy our blog about ”TypeError: the JSON object must be str, bytes or bytearray, not TextIOWrapper”. With these solutions, you can easily fix the problem. If you have any other questions or concerns about this issue, please leave a comment below. Thank you for reading, we are always excited when one of our posts can provide useful information on a topic like this!

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