Convert Python List to JSON Examples

How to convert a list to JSON in Python? You can use the json.dumps() method to convert a Python list to a JSON string. This function takes a list as an argument and returns the JSON value. The json.dumps() function converts data types such as a dictionary, string, integer, float, boolean, and None into JSON. In this article, I will explain the syntax of how to convert a list to JSON in Python, its parameters, and explain how to use it.

1. Quick Examples of Convert List to JSON

If you are in a hurry, below are some quick examples of how to convert list to JSON.

# Quick examples of convert list to JSON

# Example 1: Convert python list to JSON
numbers = [25, 36, 48, 54]
json_numbers = json.dumps(numbers)

# Example 2: Convert python  string type list to JSON
technology = ["Hadoop", "Spark", "Python"]
json_string = json.dumps(technology)

# Example 3: Convert list of dictionaries to JSON
my_dict = [{'course':'python','fee':4000}, {'duration':'60days', 'discount':1200}]
jsondict = json.dumps(my_dict)

# Example 4: Convert a list of lists to JSON
List = [[{'course':'python','fee':4000}], [{'duration':'60days', 'discount':1200}]]
jsonList = json.dumps(List)

2. Syntax of json.dumps() Function

Following is a syntax of the json.dumps() function.

# Syntax of json.dumps() function
import json
json.dumps(list)

You have to import a JSON package to use json.dumps() function.

3. Convert List to JSON

You can use the JSON module to convert a list to a JSON object. The json.dumps() function converts a Python object, in this case, a list, into a JSON string.

In the below example, first import the JSON module. Create a Python list called numbers containing some integer elements. Use json.dumps() to convert the Python list (numbers) into a JSON-formatted string (json_numbers). Print the JSON-formatted string.

# Import json
import json

# Create list of elements
numbers = [25, 36, 48, 54]
print("Original list:\n", numbers)

# Convert python list to JSON
json_numbers = json.dumps(numbers)
print("Convert list to JSON:\n",json_numbers)

Yields below output.

Here’s a simple example of how to convert a Python list to a JSON-formatted string using the json.dumps() function. For instance, you can use the json.dumps() function to convert a Python list (technology) into a JSON-formatted string (json_string).

import json

# Create list of elements
technology = ["Hadoop", "Spark", "Python"]
print("Original list:\n", technology)

# Convert python string type list to JSON
json_string = json.dumps(technology)
print("Convert string type list to JSON:\n",json_string)

Yields below output.

The output shows the original list and the corresponding JSON-formatted string. The json.dumps() function is used to convert the list into a JSON-formatted string, and in this case, the resulting JSON string represents an array of strings.

4. Convert List of Dictionaries to JSON

The json.dumps() method can be used to convert a list of dictionaries to a JSON string in Python. This function converts a list of dictionaries to JSON string without losing any original data.

import json

# Create a list of dictionaries
my_dict = [{'course':'python','fee':4000}, {'duration':'60days', 'discount':1200}]
print("Original list:\n",my_dict)

# Convert list of dictionaries to JSON
jsondict = json.dumps(my_dict)
print("Convert list of dictionaries to JSON:\n",jsondict)

# Output:
#  Original list:
#  [{'course': 'python', 'fee': 4000}, {'duration': '60days', 'discount': 1200}]
# Convert list of dictionaries to JSON:
#  [{"course": "python", "fee": 4000}, {"duration": "60days", "discount": 1200}]

5. Convert a List of Lists to JSON

You can also use the json.dumps() method to convert a Python list of lists to a JSON string, and this process preserves the original data in the lists. For example, JSON string representation of the list of lists, which you can then write to a file or send over a network connection, etc.

import json

# Create a list of dictionaries
List = [[{'course':'python','fee':4000}], [{'duration':'60days', 'discount':1200}]]
print("Original list:\n",List)

# Convert a list of lists to JSON
jsonList = json.dumps(List)
print("Convert list of lists to JSON:\n",jsonList)

# Output:
# Original list:
#  [[{'course': 'python', 'fee': 4000}], [{'duration': '60days', 'discount': 1200}]]
# Convert list of lists to JSON:
#  [[{"course": "python", "fee": 4000}], [{"duration": "60days", "discount": 1200}]

Frequently Asked Questions

Conclusion

In this article, I have explained how to convert a list to JSON in Python by using json.dumps() function with examples.

Happy Learning !!