def sort_partition(iterator):
"""
Sort a partition locally.
:param iterator:
:return:
"""
chunk_size = 500
iterator = iter(iterator)
chunks = list()
while True:
chunk = list(itertools.islice(iterator, chunk_size))
chunk.sort(key=lambda kv: key_func(kv[0]), reverse=not ascending)
chunks.append(chunk)
if len(chunk) < chunk_size:
break
else:
chunks.append(chunk.sort(key=lambda kv: key_func(kv[0]),
reverse=not ascending))
return heapq3.merge(chunks, key=lambda kv: key_func(kv[0]),
reverse=not ascending)
def test_heapq_key_reversed():
result = list(merge([['dog', 'horse'], ['cat', 'fish', 'kangaroo']],
key=len,
reverse=True))
assert result == ['dog', 'horse', 'cat', 'fish', 'kangaroo'], GENERIC_ERROR
def test_heapq_reverse():
result = list(merge([[1, 3, 5, 7], [0, 2, 4, 8], [5, 10, 15, 20], [], [25]],
key=None,
reverse=True))
assert result == [25, 5, 10, 15, 20, 1, 3, 5, 7, 0, 2, 4, 8], GENERIC_ERROR
def test_heapq_1():
result = list(merge([[1, 3, 5, 7], [0, 2, 4, 8], [5, 10, 15, 20], [], [25]],
key=None,
reverse=False))
assert result == [0, 1, 2, 3, 4, 5, 5, 7, 8, 10, 15, 20, 25], GENERIC_ERROR
