Make itertools.groupby covariant (#11032)

This commit is contained in:
Alex Waygood
2023-11-17 11:33:14 +00:00
committed by GitHub
parent 4aae235cef
commit 4982061ab3
2 changed files with 13 additions and 3 deletions

View File

@@ -10,6 +10,7 @@ _T = TypeVar("_T")
_S = TypeVar("_S")
_N = TypeVar("_N", int, float, SupportsFloat, SupportsInt, SupportsIndex, SupportsComplex)
_T_co = TypeVar("_T_co", covariant=True)
_S_co = TypeVar("_S_co", covariant=True)
_T1 = TypeVar("_T1")
_T2 = TypeVar("_T2")
_T3 = TypeVar("_T3")
@@ -84,13 +85,13 @@ class filterfalse(Iterator[_T]):
def __iter__(self) -> Self: ...
def __next__(self) -> _T: ...
class groupby(Iterator[tuple[_T, Iterator[_S]]], Generic[_T, _S]):
class groupby(Iterator[tuple[_T_co, Iterator[_S_co]]], Generic[_T_co, _S_co]):
@overload
def __new__(cls, iterable: Iterable[_T1], key: None = None) -> groupby[_T1, _T1]: ...
@overload
def __new__(cls, iterable: Iterable[_T1], key: Callable[[_T1], _T2]) -> groupby[_T2, _T1]: ...
def __iter__(self) -> Self: ...
def __next__(self) -> tuple[_T, Iterator[_S]]: ...
def __next__(self) -> tuple[_T_co, Iterator[_S_co]]: ...
class islice(Iterator[_T]):
@overload

View File

@@ -9,7 +9,7 @@ import collections
import math
import operator
import sys
from itertools import chain, combinations, count, cycle, filterfalse, islice, repeat, starmap, tee, zip_longest
from itertools import chain, combinations, count, cycle, filterfalse, groupby, islice, repeat, starmap, tee, zip_longest
from typing import Any, Callable, Hashable, Iterable, Iterator, Sequence, Tuple, Type, TypeVar, Union, overload
from typing_extensions import Literal, TypeAlias, TypeVarTuple, Unpack
@@ -272,6 +272,15 @@ def unique_everseen(iterable: Iterable[_T], key: Callable[[_T], Hashable] | None
# yield from dict(zip(map(key, t1), t2)).values()
# Slightly adapted from the docs recipe; a one-liner was a bit much for pyright
def unique_justseen(iterable: Iterable[_T], key: Callable[[_T], bool] | None = None) -> Iterator[_T]:
"List unique elements, preserving order. Remember only the element just seen."
# unique_justseen('AAAABBBCCDAABBB') --> A B C D A B
# unique_justseen('ABBcCAD', str.lower) --> A B c A D
g: groupby[_T | bool, _T] = groupby(iterable, key)
return map(next, map(operator.itemgetter(1), g))
def powerset(iterable: Iterable[_T]) -> Iterator[tuple[_T, ...]]:
"powerset([1,2,3]) --> () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)"
s = list(iterable)