def range_comparison(op, checks, value, default=None): """ An extensible ternary operator Takes an operator such as checks are tuples of sentinel values and results and must be supplied in the right order to suit the operator and prevent it matching greedily. ie. with lt checks must be in ascending order and descending or for gt """ for sentinel, result in checks: if op(value, sentinel): return result return default class TestRangeComparison(TestCase): def make_one(self): from ..utils import range_comparison return range_comparison def test_lt(self): from operator import lt FUT = self.make_one() checks = [(10, "less than 10"), (20, "less than 20"), (100, "less than 100")] self.assertEqual(FUT(lt, checks, 5), "less than 10") self.assertEqual(FUT(lt, checks, 10), "less than 20") self.assertEqual(FUT(lt, checks, 50), "less than 100") self.assertFalse(FUT(lt, checks, 100))