Method testStressfully

Lib/test/test_sort.py:43–129

(self)

class TestBase(unittest.TestCase):
    def testStressfully(self):
        # Try a variety of sizes at and around powers of 2, and at powers of 10.
        sizes = [0]
        for power in range(1, 10):
            n = 2 ** power
            sizes.extend(range(n-1, n+2))
        sizes.extend([10, 100, 1000])

        class Complains(object):
            maybe_complain = True

            def __init__(self, i):
                self.i = i

            def __lt__(self, other):
                if Complains.maybe_complain and random.random() < 0.001:
                    if verbose:
                        print("        complaining at", self, other)
                    raise RuntimeError
                return self.i < other.i

            def __repr__(self):
                return "Complains(%d)" % self.i

        class Stable(object):
            def __init__(self, key, i):
                self.key = key
                self.index = i

            def __lt__(self, other):
                return self.key < other.key

            def __repr__(self):
                return "Stable(%d, %d)" % (self.key, self.index)

        for n in sizes:
            x = list(range(n))
            if verbose:
                print("Testing size", n)

            s = x[:]
            check("identity", x, s)

            s = x[:]
            s.reverse()
            check("reversed", x, s)

            s = x[:]
            random.shuffle(s)
            check("random permutation", x, s)

            y = x[:]
            y.reverse()
            s = x[:]
            check("reversed via function", y, s, lambda a, b: (b>a)-(b<a))

            if verbose:
                print("    Checking against an insane comparison function.")