Python How to Convert JSON to List Easily

Use json.loads(json_string) to convert a JSON string representing a list into a Python list.

Examples

Input"[1, 2, 3]"

Output[1, 2, 3]

Input"[\"apple\", \"banana\", \"cherry\"]"

Output["apple", "banana", "cherry"]

Input"[]"

Output[]

How to Think About It

To convert JSON to a list, first understand that JSON is a string format. You need to parse this string into Python objects. If the JSON string represents a list, parsing it will give you a Python list.

Algorithm

1

Get the JSON string input.

2

Use a JSON parsing function to convert the string to a Python object.

3

Return the Python list obtained from parsing.

Code

python

import json

json_string = '["apple", "banana", "cherry"]'
python_list = json.loads(json_string)
print(python_list)

Output

['apple', 'banana', 'cherry']

Dry Run

Let's trace converting '["apple", "banana", "cherry"]' to a Python list.

1

Input JSON string

'["apple", "banana", "cherry"]'

2

Parse JSON string

json.loads('["apple", "banana", "cherry"]')

3

Output Python list

['apple', 'banana', 'cherry']

Step	Action	Value
1	Input JSON string	["apple", "banana", "cherry"]
2	Parse JSON string	['apple', 'banana', 'cherry']
3	Output Python list	['apple', 'banana', 'cherry']

Why This Works

Step 1: JSON is a string format

The input is a string that looks like a list but is actually text.

Step 2: Use json.loads to parse

The json.loads function reads the string and converts it into Python objects.

Step 3: Result is a Python list

If the JSON string represents a list, the result is a Python list you can use in your code.

Alternative Approaches

Using ast.literal_eval

python

import ast
json_string = '[1, 2, 3]'
python_list = ast.literal_eval(json_string)
print(python_list)

This works if the JSON is simple and safe, but json.loads is preferred for strict JSON parsing.

Manual parsing (not recommended)

python

json_string = '[1, 2, 3]'
python_list = json_string.strip('[]').split(', ')
print(python_list)

This is fragile and only works for very simple lists of strings or numbers.

Complexity: O(n) time, O(n) space

Time Complexity

Parsing the JSON string takes time proportional to its length, so it's O(n).

Space Complexity

The parsed list uses extra memory proportional to the size of the JSON string, so O(n).

Which Approach is Fastest?

Using json.loads is efficient and safe; alternatives like ast.literal_eval are slower and less strict.

Approach	Time	Space	Best For
json.loads	O(n)	O(n)	Standard JSON parsing, safe and fast
ast.literal_eval	O(n)	O(n)	Simple Python literals, less strict
Manual parsing	O(n)	O(n)	Very simple cases, fragile