listless
listless
⚓︎
Listless = generators, iterators, and async iterators, Oh My!
Functions⚓︎
listless.aiterable(it: Union[Iterable[_T], AsyncIterable[_T]]) -> AsyncIterator[_T]
⚓︎
Convert any-iterable to an async iterator
Examples:
>>> from asyncio import run
>>> plain_jane_list = list(range(10))
>>> async def consume_aiterable(it):
... stuff = []
... async for el in aiterable(it):
... stuff.append(el)
... return stuff
>>> run(consume_aiterable(plain_jane_list))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> async def async_gen():
... for b in range(10):
... yield b
>>> run(consume_aiterable(async_gen()))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> class AsyncIterable:
... def __aiter__(self):
... return async_gen()
>>> run(consume_aiterable(AsyncIterable()))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Source code in libs/listless/listless/__init__.py
72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 |
|
listless.chunk(it: Union[Sequence[_T], Collection[_T]], n: int) -> Iterable[Union[Sequence[_T], Collection[_T], str]]
⚓︎
Yield chunks of size n from an iterable/sequence/collection
Examples:
>>> list(chunk([1, 2, 3, 4, 5, 6], 3))
[[1, 2, 3], [4, 5, 6]]
Source code in libs/listless/listless/__init__.py
331 332 333 334 335 336 337 338 339 340 341 |
|
listless.chunks(it: Union[Sequence[_T], Collection[_T]], chunk_size: int) -> Iterable[Union[Sequence[_T], Collection[_T], str]]
⚓︎
Yield chunks of something slice-able with length <= chunk_size
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Iterable[Any]
|
Iterable to chunk |
required |
chunk_size |
int
|
Size of the chunks |
required |
Returns:
Type | Description |
---|---|
Iterable[Union[Sequence[_T], Collection[_T], str]]
|
Iterable of the chunks |
Examples:
>>> list(chunks([1, 2, 3, 4, 5, 6], 3))
[[1, 2, 3], [4, 5, 6]]
>>> list(chunks([1, 2, 3, 4, 5, 6], 2))
[[1, 2], [3, 4], [5, 6]]
>>> list(chunks('abcdefghijklmnopqrstuvwxyz', 13))
['abcdefghijklm', 'nopqrstuvwxyz']
Can chunk where it length is not divisible by chunk_size
>>> list(chunks('abcdefghijklmnopqrstuvwxyz', 4))
['abcd', 'efgh', 'ijkl', 'mnop', 'qrst', 'uvwx', 'yz']
>>> list(chunks((el for el in range(10)), 4))
[(0, 1, 2, 3), (4, 5, 6, 7), (8, 9)]
Source code in libs/listless/listless/__init__.py
290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 |
|
listless.chunkseq(it: Sequence[_T], n: int) -> Iterable[Sequence[_T]]
⚓︎
Yield chunks of size n from a Sequence
Source code in libs/listless/listless/__init__.py
264 265 266 |
|
listless.chunkstr(string: str, n: int) -> Iterable[str]
⚓︎
Yield chunks of size n from a string
Source code in libs/listless/listless/__init__.py
269 270 271 |
|
listless.enumerate_async(it: AnyIterable[_T], start: int = 0) -> AsyncIterator[Tuple[int, _T]]
async
⚓︎
Enumerate (async) over any iterable
Examples:
>>> async def t():
... return [item async for item in enumerate_async('abcde')]
>>> from asyncio import run as aiorun
>>> aiorun(t())
[(0, 'a'), (1, 'b'), (2, 'c'), (3, 'd'), (4, 'e')]
Source code in libs/listless/listless/__init__.py
732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 |
|
listless.exhaust(it: Iterable[_T], *, maxlen: Optional[int] = 0) -> Deque[_T]
⚓︎
Exhaust an interable; useful for evaluating a map object.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Iterable[_T]
|
Iterable to exhaust |
required |
maxlen |
Optional[int]
|
Maximum length of the deque; if 0, deque is unbounded |
0
|
Examples:
>>> a = [1, 2, 3, 4, 5, 6]
>>> a_map = map(lambda x: x*2, a)
>>> a_exhausted = exhaust(a_map)
>>> a = [1, 2, 3, 4, 5, 6]
>>> b = []
>>> def square_and_append_to_b(n):
... b.append(n**2)
>>> a_map = map(square_and_append_to_b, a)
>>> a_exhausted = exhaust(a_map)
>>> a_exhausted
deque([], maxlen=0)
>>> b
[1, 4, 9, 16, 25, 36]
>>> another_map = map(lambda x: x*2, a)
>>> another_exhausted = exhaust(another_map, maxlen=2)
>>> another_exhausted
deque([10, 12], maxlen=2)
Source code in libs/listless/listless/__init__.py
344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 |
|
listless.filter_is_none(it: Iterable[Union[_T, None]]) -> Iterable[_T]
⚓︎
Filter values that is None
; checkout filter_none for false-y filtering
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Iterable[Union[_T, None]]
|
Iterable possibly containing None/False-y values |
required |
Returns:
Type | Description |
---|---|
Iterable[_T]
|
filter object with None values excluded |
Examples:
>>> list(filter_is_none([1, 2, None, 3, 4, None, 5, "a_string???"]))
[1, 2, 3, 4, 5, 'a_string???']
>>> list(filter_is_none([-1, 0, 1, '', 's', None, [], ['s'], {}]))
[-1, 0, 1, '', 's', [], ['s'], {}]
Source code in libs/listless/listless/__init__.py
461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 |
|
listless.filter_none(it: Iterable[Union[_T, None]]) -> Iterable[_T]
⚓︎
Filter None
values from an iterable
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Iterable[Union[_T, None]]
|
Iterable possibly containing None values |
required |
Returns:
Type | Description |
---|---|
Iterable[_T]
|
filter object with None values excluded |
Examples:
>>> list(filter_none([1, 2, None, 3, 4, None, 5, "a_string???"]))
[1, 2, 3, 4, 5, 'a_string???']
>>> list(filter_none([1, 2, '', 3, 4, None, 5, "a_string???", []]))
[1, 2, 3, 4, 5, 'a_string???']
>>> list(filter_none([-1, 0, 1, '', 's', None, [], ['s'], {}]))
[-1, 1, 's', ['s']]
This function is p simple and importing it and calling it might actually
be more characters to type than just using filter(None, ya_iterable)
but it is a fire thing to know and you can totally show off with this,
also outperforms the list/gen comprehension equivalent, by quite a bit::
import random
res = [random.randrange(1, 300, 1) for i in range(1000)]
lists = [
res
]
for i in range(40):
random.shuffle(res)
lists.append(res)
def filter_one(it):
return (i for i in it if i is not None)
def filter_two(it):
return filter(None, it)
Timing the first function (generator comprehension)::
%%timeit
for i in range(100):
for l in lists:
a = list(filter_one(l))
180 ms +/- 184 µs/loop (mean +/- std. dev. of 7 runs, 10 loops each)
Timing the second function (filter)::
%%timeit
for i in range(100):
for l in lists:
a = list(filter_two(l))
42.5 ms +/- 112 µs/loop (mean +/- std. dev. of 7 runs, 10 loops each)
Source code in libs/listless/listless/__init__.py
399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 |
|
listless.flatten(*args: Union[_T, Iterable[_T]]) -> Iterable[_T]
⚓︎
Flatten possibly nested iterables of sequences to a flat list
Examples:
>>> list(flatten("cmd", ["uno", "dos", "tres"]))
['cmd', 'uno', 'dos', 'tres']
>>> list(flatten("cmd", ["uno", "dos", "tres", ["4444", "five"]]))
['cmd', 'uno', 'dos', 'tres', '4444', 'five']
>>> list(flatten("cmd", ["uno", "dos", "tres", ["4444", "five", 123]]))
['cmd', 'uno', 'dos', 'tres', '4444', 'five', 123]
Source code in libs/listless/listless/__init__.py
481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 |
|
listless.flatten_seq(*args: Union[_T, Sequence[_T]], anystr: bool = False) -> Iterable[_T]
⚓︎
Flatten possibly nested iterables of sequences to a flat list
Examples:
>>> list(flatten_seq("cmd", ["uno", "dos", "tres"]))
['cmd', 'uno', 'dos', 'tres']
>>> list(flatten_seq("cmd", ["uno", "dos", "tres", ["4444", "five"]]))
['cmd', 'uno', 'dos', 'tres', '4444', 'five']
Source code in libs/listless/listless/__init__.py
504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 |
|
listless.flatten_strings(*args: Union[_T, Iterable[_T]]) -> Iterable[str]
⚓︎
Flatten possibly nested iterables of sequences to a list of strings
Examples:
>>> from listless import flatten_strings
>>> list(flatten_strings("cmd", ["uno", "dos", "tres"]))
['cmd', 'uno', 'dos', 'tres']
>>> list(flatten_strings("cmd", ["uno", "dos", "tres", ["4444", "five", 123]]))
['cmd', 'uno', 'dos', 'tres', '4444', 'five', '123']
Source code in libs/listless/listless/__init__.py
526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 |
|
listless.is_sequence(seq: Any) -> bool
⚓︎
Check if an object is a sequence
Examples:
>>> is_sequence([1, 2, 3])
True
>>> is_sequence('abc')
False
>>> is_sequence(1)
False
>>> is_sequence(None)
False
>>> is_sequence(True)
False
>>> is_sequence((1, 2, 3))
True
Source code in libs/listless/listless/__init__.py
236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 |
|
listless.is_subscriptable(obj: Any) -> bool
⚓︎
Check if an object is subscriptable
Examples:
>>> is_subscriptable([1, 2, 3])
True
>>> is_subscriptable('abc')
True
>>> is_subscriptable(1)
False
>>> is_subscriptable(None)
False
>>> is_subscriptable(True)
False
>>> is_subscriptable((1, 2, 3))
True
Source code in libs/listless/listless/__init__.py
211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 |
|
listless.it_product(it: Iterable[Union[int, float]]) -> Union[int, float]
⚓︎
Product of all the elements in an iterable of numbers
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Iterable[Union[int, float]]
|
Iterable of numbers |
required |
Returns:
Type | Description |
---|---|
Union[int, float]
|
The product of all the numbers in the iterable |
Examples:
>>> it_product([1, 2, 3, 4])
24
>>> it_product(tuple([1, 2, 3, 4]))
24
>>> it_product([-1, -2, -3, 4])
-24
>>> it_product([-1, -2, 3, 4, 0.5])
12.0
Source code in libs/listless/listless/__init__.py
574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 |
|
listless.itlen(iterable: Iterable[Any], unique: bool = False) -> int
⚓︎
Return the length/num-items in an iterable
This consumes the iterable.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
iterable |
Iterable[Any]
|
Iterable |
required |
unique |
bool
|
Count unique values |
False
|
Returns:
Type | Description |
---|---|
int
|
Length of an iterable |
Examples:
>>> itlen(range(10))
10
>>> itlen(x for x in range(1000000) if x % 3 == 0)
333334
>>> l = [x for x in range(1000000) if x % 3 == 0]
>>> itlen(l + l, unique=True)
333334
Source code in libs/listless/listless/__init__.py
545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 |
|
listless.list_async(itr: AnyIterable[_T]) -> List[_T]
async
⚓︎
Consume any iterable (async/sync) and return as a list
Examples:
>>> async def t():
... return await list_async(range(5))
>>> from asyncio import run as aiorun
>>> aiorun(t())
[0, 1, 2, 3, 4]
Source code in libs/listless/listless/__init__.py
704 705 706 707 708 709 710 711 712 713 714 715 |
|
listless.next_async(it: AnyIterator[_T]) -> _T
async
⚓︎
Return the next item of any iterator/iterable (sync or async
Examples:
>>> from asyncio import run as aiorun
>>> async def async_gen():
... for b in range(10):
... yield b
>>> gen = async_gen()
>>> async def fn(gen):
... first = await next_async(gen)
... second = await next_async(gen)
... return first, second
>>> aiorun(fn(gen))
(0, 1)
>>> aiorun(fn(iter(range(2))))
(0, 1)
Source code in libs/listless/listless/__init__.py
676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 |
|
listless.nyield(it: Sequence[_T], n: int) -> Iterable[_T]
⚓︎
Yield the first n items of an iterable
Examples:
>>> list(nyield([1, 2, 3, 4, 5, 6], 3))
[1, 2, 3]
Source code in libs/listless/listless/__init__.py
200 201 202 203 204 205 206 207 208 |
|
listless.pairs(it: Iterable[_T]) -> Iterable[Tuple[_T, _T]]
⚓︎
Yield pairs of adjacent elements
Examples:
>>> list(pairs([1, 2, 3, 4]))
[(1, 2), (2, 3), (3, 4)]
>>> list(pairs(['a', 'b', 'c']))
[('a', 'b'), ('b', 'c')]
>>> list(pairs('abc'))
[('a', 'b'), ('b', 'c')]
Source code in libs/listless/listless/__init__.py
113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 |
|
listless.partition(it: Sequence[_T], n: int, *, pad: bool = False, padval: Any = None) -> Iterable[Sequence[_T]]
⚓︎
Partition an iterable into chunks of size n
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Sequence[_T]
|
Iterable to partition |
required |
n |
int
|
Size of the partition chunks |
required |
pad |
bool
|
Pad parts with padval if True, else do not pad |
False
|
padval |
Any
|
Value to pad with |
None
|
Returns:
Type | Description |
---|---|
Iterable[Sequence[_T]]
|
Iterable of the partitioned chunks |
Examples:
>>> list(partition([1, 2, 3, 4, 5, 6], 3))
[(1, 2, 3), (4, 5, 6)]
>>> list(partition([1, 2, 3, 4, 5, 6], 2))
[(1, 2), (3, 4), (5, 6)]
>>> for part in partition('abcdefghijklmnopqrstuvwxyz', 13):
... print(part)
('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm')
('n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z')
>>> for part in partition('abcdefghijklmnopqrstuvwxyz', 4):
... print(part)
('a', 'b', 'c', 'd')
('e', 'f', 'g', 'h')
('i', 'j', 'k', 'l')
('m', 'n', 'o', 'p')
('q', 'r', 's', 't')
('u', 'v', 'w', 'x')
>>> for part in partition('abcdefghijklmnopqrstuvwxyz', 4, pad=True):
... print(part)
('a', 'b', 'c', 'd')
('e', 'f', 'g', 'h')
('i', 'j', 'k', 'l')
('m', 'n', 'o', 'p')
('q', 'r', 's', 't')
('u', 'v', 'w', 'x')
('y', 'z', None, None)
>>> for part in partition('abcdefghijklmnopqrstuvwxyz', 4, pad=True, padval=...):
... print(part)
('a', 'b', 'c', 'd')
('e', 'f', 'g', 'h')
('i', 'j', 'k', 'l')
('m', 'n', 'o', 'p')
('q', 'r', 's', 't')
('u', 'v', 'w', 'x')
('y', 'z', Ellipsis, Ellipsis)
Raises:
Type | Description |
---|---|
TypeError
|
If |
ValueError
|
if |
Source code in libs/listless/listless/__init__.py
130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 |
|
listless.set_async(itr: AnyIterable[_T]) -> Set[_T]
async
⚓︎
Consume any iterable (async/sync) and return as a list
Examples:
>>> async def t():
... return await set_async(range(5))
>>> from asyncio import run as aiorun
>>> aiorun(t())
{0, 1, 2, 3, 4}
Source code in libs/listless/listless/__init__.py
718 719 720 721 722 723 724 725 726 727 728 729 |
|
listless.spliterable(it: Iterable[_T], fn: Callable[[_T], bool]) -> Tuple[Iterable[_T], Iterable[_T]]
⚓︎
1 generator + True/False-function => 2 generators (True-gen, False-gen)
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Iterable[_T]
|
iterable to split |
required |
fn |
Callable[[_T], bool]
|
Function to evaluate iterable elements and returns True or False |
required |
Returns:
Type | Description |
---|---|
Tuple[Iterable[_T], Iterable[_T]]
|
tuple of generators: (gen_predicate_true, gen_predicate_false) |
Examples:
>>> is_even = lambda n: n % 2 == 0
>>> a, b = spliterable(range(10), is_even)
>>> list(a)
[0, 2, 4, 6, 8]
>>> list(b)
[1, 3, 5, 7, 9]
Source code in libs/listless/listless/__init__.py
597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 |
|
listless.unique(it: Iterable[_T], key: Optional[Callable[[_T], _K]] = None) -> Iterable[_T]
⚓︎
Alias for unique_gen
Examples:
>>> l = [*range(10), *range(10)]
>>> list(unique(l))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> tuple(unique(['cat', 'mouse', 'dog', 'hen'], key=len))
('cat', 'mouse')
Source code in libs/listless/listless/__init__.py
657 658 659 660 661 662 663 664 665 666 667 668 |
|
listless.unique_gen(it: Iterable[_T], key: Optional[Callable[[_T], _K]] = None) -> Iterable[_T]
⚓︎
Yield unique values (ordered) from an iterable
Parameters:
Name | Type | Description | Default |
---|---|---|---|
it |
Iterable[_T]
|
Iterable |
required |
key |
Optional[Callable[[_T], _K]]
|
Optional callable to use to get the key to use for uniqueness |
None
|
Returns:
Type | Description |
---|---|
Iterable[_T]
|
Generator that yields unique values as they appear |
Examples:
>>> l = [*range(10), *range(10)]
>>> list(unique_gen(l))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> tuple(unique_gen(['cat', 'mouse', 'dog', 'hen'], key=len))
('cat', 'mouse')
Source code in libs/listless/listless/__init__.py
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 |
|
listless.xmap(func: Callable[[_T], _R], it: Iterable[_T], *, maxlen: Optional[int] = 0) -> Deque[_R]
⚓︎
Apply a function to each element of an iterable immediately
Parameters:
Name | Type | Description | Default |
---|---|---|---|
func |
Callable[[_T], _R]
|
Function to apply to each element |
required |
it |
Iterable[_T]
|
iterable to apply func to |
required |
maxlen |
Optional[int]
|
Maximum length of the deque; if 0, deque is unbounded |
0
|
Returns:
Type | Description |
---|---|
Deque[_R]
|
Deque of the possible results if maxlen is greater than 0 |
Examples:
>>> xmap(lambda x: x*2, list(range(1, 7)))
deque([], maxlen=0)
>>> xmap(lambda x: x*2, list(range(1, 7)), maxlen=2)
deque([10, 12], maxlen=2)
>>> xmap(lambda x: x*2, list(range(1, 7)), maxlen=None)
deque([2, 4, 6, 8, 10, 12])
Source code in libs/listless/listless/__init__.py
374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 |
|
listless.zip_async(*iterables: AnyIterable[Any]) -> AsyncIterator[Tuple[Any, ...]]
async
⚓︎
Async verstion of builtin zip function
Example
from asyncio import run as aiorun from listless import zip_async from listless import list_async, iter_async # for fake async iters a, b, c = iter_async(range(4)), iter_async(range(6)), iter_async(range(5)) aiorun(list_async(zip_async(a, b, c))) [(0, 0, 0), (1, 1, 1), (2, 2, 2), (3, 3, 3)]
Source code in libs/listless/listless/__init__.py
751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 |
|
Modules⚓︎
listless.__about__
⚓︎
Package metadata/info
listless.__main__
⚓︎
pkg entry ~ python -m listless