Testing Add function can support a random number of numbers

stringcalculator-test.py

import unittest
from stringcalculator import add

class TestStringCalculator(unittest.TestCase):

  def test_add_empty_string_return_zero(self):
    self.assertEqual(add(''), 0)
    
  def test_add_one_number_will_return_itself(self):
    self.assertEqual(add('2'), 2)
    self.assertEqual(add('24'), 24)
    
  def test_add_two_numbers_separated_by_comma(self):
    self.assertEqual(add('1,2'),3)
    self.assertEqual(add('21,9'),30)
    
  def test_add_supports_random_number_of_numbers(self):  
    self.assertEqual(add('1,3,9,6'), 19)
    self.assertEqual(add('1,4,7,9,8,10,11,23'),72)