oxedyne/fe2o3 — fe2o3_text/tests/detect_corpus/python/generators.txt

1.4 KiB, 1 run

created by r1870400018:12030, which is this file's identity for as long as the history lasts, whatever it is later renamed to

1	from typing import Generator, Iterator, Iterable
2	import itertools
3
4
5	def fibonacci() -> Generator[int, None, None]:
6	a, b = 0, 1
7	while True:
8	yield a
9	a, b = b, a + b
10
11
12	def primes() -> Generator[int, None, None]:
13	"""Sieve of Eratosthenes, unbounded."""
14	composites = {}
15	n = 2
16	while True:
17	if n not in composites:
18	yield n
19	composites[n * n] = [n]
20	else:
21	for prime in composites[n]:
22	composites.setdefault(prime + n, []).append(prime)
23	del composites[n]
24	n += 1
25
26
27	def take(n: int, iterable: Iterable) -> list:
28	return list(itertools.islice(iterable, n))
29
30
31	def windowed(iterable: Iterable, size: int) -> Generator:
32	it = iter(iterable)
33	window = []
34	for _ in range(size):
35	try:
36	window.append(next(it))
37	except StopIteration:
38	return
39	yield tuple(window)
40	for item in it:
41	window.pop(0)
42	window.append(item)
43	yield tuple(window)
44
45
46	def batched(iterable: Iterable, n: int) -> Generator:
47	it = iter(iterable)
48	while True:
49	batch = list(itertools.islice(it, n))
50	if not batch:
51	return
52	yield batch
53
54
55	if __name__ == '__main__':
56	print(f"first 10 fibs: {take(10, fibonacci())}")
57	print(f"first 10 primes: {take(10, primes())}")
58	print(f"windows: {list(windowed(range(6), 3))}")
59	print(f"batches: {list(batched(range(10), 3))}")