def test_get_calc_from_start_or_end(self): string1 = "$12*17" assert Commons.get_calc_from_start_or_end(string1) == "12*17", "Failed to get calculation from end" string2 = "cos(tan(12+t+15))" assert Commons.get_calc_from_start_or_end(string2) == "cos(tan(12+", "Failed to get calculation from start" string3 = "hello" assert Commons.get_calc_from_start_or_end(string3) is None, "Did not return None when no calculation found" string4 = "£13.50" assert Commons.get_calc_from_start_or_end(string4) == "13.50", "Failed to get number from end" string5 = "23f234" assert Commons.get_calc_from_start_or_end(string5) == "23", "Function should prioritise calculation at start" string6 = "tasty pie" assert Commons.get_calc_from_start_or_end(string6) == " pie", "Bit weird, but this should work too"