import asyncio import decimal import unittest def tearDownModule(): asyncio.set_event_loop_policy(None) @unittest.skipUnless(decimal.HAVE_CONTEXTVAR, "decimal is built with a thread-local context") class DecimalContextTest(unittest.TestCase): def test_asyncio_task_decimal_context(self): async def fractions(t, precision, x, y): with decimal.localcontext() as ctx: ctx.prec = precision a = decimal.Decimal(x) / decimal.Decimal(y) await asyncio.sleep(t) b = decimal.Decimal(x) / decimal.Decimal(y ** 2) return a, b async def main(): r1, r2 = await asyncio.gather( fractions(0.1, 3, 1, 3), fractions(0.2, 6, 1, 3)) return r1, r2 r1, r2 = asyncio.run(main()) self.assertEqual(str(r1[0]), '0.333') self.assertEqual(str(r1[1]), '0.111') self.assertEqual(str(r2[0]), '0.333333') self.assertEqual(str(r2[1]), '0.111111')