Solving 'TypeError: Object of Type int64 is not JSON Serializable' Error: Solutions and Tips

If you're a developer working with Python and JSON, you might have encountered the "TypeError: Object of type int64 is not JSON serializable" error. This error occurs when you try to serialize a NumPy int64 object to JSON, which is not supported by default.

In this guide, we'll explore the different solutions and tips to fix this error and get your code running smoothly again.

Solution 1: Convert int64 to int

One simple solution for this error is to convert the int64 object to a regular integer before serializing it to JSON. This can be done using the int() function.

Here's an example code snippet:

import json
import numpy as np

# Create a NumPy int64 object
num = np.int64(42)

# Convert int64 to int
num = int(num)

# Serialize to JSON
json.dumps(num)

This code will output the serialized JSON string without any errors.

Solution 2: Use a Custom Encoder

Another solution is to create a custom encoder that can handle int64 objects and serialize them to JSON. This can be done by subclassing the json.JSONEncoder class and overriding the default() method.

Here's an example code snippet:

import json
import numpy as np

# Create a custom encoder
class MyEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, np.int64):
            return int(obj)
        return super().default(obj)

# Create a NumPy int64 object
num = np.int64(42)

# Serialize to JSON using custom encoder
json.dumps(num, cls=MyEncoder)

This code will also output the serialized JSON string without any errors.

Solution 3: Use a Third-Party Library

If you don't want to create a custom encoder yourself, you can use a third-party library that already provides this functionality. One such library is simplejson.

Here's an example code snippet:

import simplejson as json
import numpy as np

# Create a NumPy int64 object
num = np.int64(42)

# Serialize to JSON using simplejson
json.dumps(num, ignore_nan=True)

This code will output the serialized JSON string without any errors.

FAQ

Q1. What is the 'TypeError: Object of type int64 is not JSON serializable' error?

This error occurs when you try to serialize a NumPy int64 object to JSON, which is not supported by default.

Q2. Why does this error occur?

JSON only supports a limited set of data types, and int64 is not one of them. This means that you need to convert int64 objects to a supported data type before serializing them to JSON.

Q3. How do I convert int64 to int?

You can use the int() function in Python to convert an int64 object to a regular integer.

Q4. How do I create a custom encoder?

You can subclass the json.JSONEncoder class and override the default() method to create a custom encoder that can handle int64 objects.

Q5. Can I use a third-party library to fix this error?

Yes, there are several third-party libraries that provide this functionality, such as simplejson.