Fastest way to parse JSON strings into numpy arrays

Question

I have huge json objects containing 2D lists of coordinates that I need to transform into numpy arrays for processing.

However using json.loads followed wi

Answer 1

Since JSON syntax is really near to Python syntax, I suggest you to use ast.literal_eval. It may be faster…

import ast
import numpy as np

json_input = """{"rings" : [[[-8081441.0, 5685214.0],
                             [-8081446.0, 5685216.0],
                             [-8081442.0, 5685219.0],
                             [-8081440.0, 5685211.0],
                             [-8081441.0, 5685214.0]]]}"""

rings = ast.literal_eval(json_input)
numpy_2d_arrays = [np.array(ring) for ring in rings["rings"]]

Give it a try. And tell us.