Kumite

import codewars_test as test
from solution import clean
import random as rand
import string as s


@test.describe("Test cases")
def test_group():
    @test.it("Fixed test cases")
    def fixed():
        test.assert_equals(clean("2 plus 2 is 4"), " plus  is ")
        test.assert_equals(clean("0123456789"), "")
        test.assert_equals(clean("3h9fk37cf"), "hfkcf")
    
    @test.it("Random test cases")
    def random():
        def sol(str):
            return "".join("" if x.isdigit() else x for x in str)
        for i in range(20):
            bla = s.ascii_letters + s.digits
            bleh = [x for x in bla]
            rand.shuffle(bleh)
            bleh = "".join(bleh)
            print("asserting for string " + bleh)
            test.assert_equals(clean(bleh), sol(bleh))