cpython/Lib/test/json_tests/test_float.py

import math
from unittest import TestCase

import json

class TestFloat(TestCase):
    def test_floats(self):
        for num in [1617161771.7650001, math.pi, math.pi**100, math.pi**-100, 3.1]:
            self.assertEqual(float(json.dumps(num)), num)
            self.assertEqual(json.loads(json.dumps(num)), num)

    def test_ints(self):
        for num in [1, 1<<32, 1<<64]:
            self.assertEqual(json.dumps(num), str(num))
            self.assertEqual(int(json.dumps(num)), num)