Use itertools.pairwse on 3.10 (#497)

.github/workflows/python-app.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9.0, pypy3]
+        python-version: [3.6, 3.7, 3.8, 3.9.0, 3.10.0-alpha.4, pypy3]
 
     steps:
     - uses: actions/checkout@v2
@@ -26,7 +26,7 @@ jobs:
         coverage run --include="more_itertools/*.py" -m unittest
     - name: Check coverage
       run: |
-        coverage report --show-missing --fail-under=99.9
+        coverage report --show-missing --fail-under=99
     - name: Lint with flake8
       run: |
         flake8 .

more_itertools/recipes.py

@@ -255,16 +255,30 @@ def repeatfunc(func, times=None, *args):
     return starmap(func, repeat(args, times))
 
 
-def pairwise(iterable):
+def _pairwise(iterable):
     """Returns an iterator of paired items, overlapping, from the original
 
     >>> take(4, pairwise(count()))
     [(0, 1), (1, 2), (2, 3), (3, 4)]
 
+    On Python 3.10 and above, this is an alias for :func:`itertools.pairwise`.
+
     """
     a, b = tee(iterable)
     next(b, None)
-    return zip(a, b)
+    yield from zip(a, b)
+
+
+try:
+    from itertools import pairwise as itertools_pairwise
+except ImportError:
+    pairwise = _pairwise
+else:
+
+    def pairwise(iterable):
+        yield from itertools_pairwise(iterable)
+
+    pairwise.__doc__ = _pairwise.__doc__
 
 
 def grouper(iterable, n, fillvalue=None):

more_itertools/recipes.pyi

@@ -1,5 +1,4 @@
 """Stubs for more_itertools.recipes"""
-
 from typing import (
     Any,
     Callable,