async def test_islice_consumption():
"""Check that islice does not overly consume the iterable."""
iterable = await aitertools.aiter(range(10))
assert (await aitertools.alist(
aitertools.islice(iterable, 3)
)) == list(range(3))
assert (await aitertools.alist(iterable)) == list(range(3, 10))
async def test_islice_no_stop():
"""Check that islice exhausts the iterable when no stop is given."""
assert (await aitertools.alist(
aitertools.islice(range(10), None)
)) == list(range(10))
assert (await aitertools.alist(
aitertools.islice(range(10), None, None)
)) == list(range(10))
assert (await aitertools.alist(
aitertools.islice(range(10), None, None, None)
)) == list(range(10))
assert (await aitertools.alist(
aitertools.islice(range(10), 2, None)
)) == list(range(2, 10))
assert (await aitertools.alist(
aitertools.islice(range(10), 1, None, 2)
)) == list(range(1, 10, 2))
async def test_islice_invalid_arguments(args):
"""Check that islice raises ValueError when input is invalid."""
with pytest.raises(ValueError):
await aitertools.anext(aitertools.islice(range(10), *args))
async def test_islice_exausted_iterable(slice_args, range_args):
"""Check that islice stops when the wrapped iterable is exhausted."""
assert (await aitertools.alist(
aitertools.islice(range(100), *slice_args)
)) == list(range(*range_args))
async def test_islice_matches_range(args):
"""Check happy path for islice using equivalent range arguments."""
assert (await aitertools.alist(
aitertools.islice(range(100), *args)
)) == list(range(*args))
async def generator():
with open(file_path) as csvf:
async for line in aitertools.islice(csvf, slice_size):
yield line.encode("utf-8")