def test_can_get_slices(self):
ll = LazyList(self.iterator([6, 5, 4, 3, 2, 1]))
assert ll[1:3] == [5, 4]
assert ll[:4] == [6, 5, 4, 3]
assert ll[4:] == [2, 1]
ll = LazyList(self.iterator([6, 5, 4, 3, 2, 1]))
assert ll[4:7] == [2, 1]
def test_open_ended_set_slice_empties_iterator(self):
ll = LazyList(self.iterator([6, 5, 4, 3, 2, 1]))
assert ll[2] == 4
ll[1:] = [7, 8, 9] # wipes generator
assert ll == [6, 7, 8, 9]
with pytest.raises(IndexError):
ll[4]
def test_can_delete_slices(self):
ll = LazyList(self.iterator([6, 5, 4, 3, 2, 1]))
assert ll[2] == 4
del ll[1:]
assert ll[2] == 2
del ll[1:2]
assert ll[2] == 1
assert len(ll) == 3
assert ll == [6, 2, 1]
def test_simple_iterator_random_access(self):
ll = LazyList(self.iterator([6, 5, 4, 3, 2, 1]))
assert len(ll) == 0
assert ll[2] == 4
assert ll == [6, 5, 4]
assert ll[0] == 6
assert len(ll) == 3
assert ll[5] == 1
assert len(ll) == 6
assert ll == [6, 5, 4, 3, 2, 1]
def test_can_insert_slices(self):
ll = LazyList(self.iterator([6, 5, 4, 3, 2, 1]))
assert ll[2] == 4
ll[1:3] = [7, 8, 9]
assert ll == [6, 7, 8, 9]
assert ll[4] == 3
ll[5:6] = [10, 11, 12] # extract int(2) and immediately replace it
assert ll == [6, 7, 8, 9, 3, 10, 11, 12]
with pytest.raises(IndexError):
ll[10] # extracts int(1) to index 8, but fails to extract any more
assert ll == [6, 7, 8, 9, 3, 10, 11, 12, 1]
def test_simple_iterator_access_in_sequence(self):
ll = LazyList(self.iterator([6, 5, 4]))
assert len(ll) == 0
assert ll[0] == 6
assert len(ll) == 1
assert ll[1] == 5
assert len(ll) == 2
assert ll[2] == 4
assert len(ll) == 3
assert ll == [6, 5, 4]
with pytest.raises(IndexError):
ll[3]
assert ll == [6, 5, 4]
def test_can_append_before_iterator_exhausted(self):
ll = LazyList(self.iterator([6, 5, 4]))
assert ll[0] == 6
ll.append(3)
ll.append(2)
ll.append(1)
assert ll[3] == 1
assert len(ll) == 4
assert ll[4] == 5
assert ll[5] == 4
assert len(ll) == 6
with pytest.raises(IndexError):
ll[6]
assert ll == [6, 3, 2, 1, 5, 4]
def test_can_append_after_iterator_exhausted(self):
ll = LazyList(self.iterator([6, 5, 4]))
assert ll[2] == 4
ll.append(3)
assert ll[3] == 3
assert len(ll) == 4
def test_empty_iterator(self):
ll = LazyList(self.iterator([]))
assert len(ll) == 0
with pytest.raises(IndexError):
ll[0]
assert ll == []