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"
