Patch asyncio

.github/workflows/main.yml

@@ -15,11 +15,6 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
         python-version: [ 3.6, 3.7, 3.8, 3.9 ]
-        exclude:
-          - os: windows-latest
-            python-version: 3.8
-          - os: windows-latest
-            python-version: 3.9
     env:
         OS: ${{ matrix.os }}
         PYTHON: '3.9'

nbclient/__init__.py

@@ -13,5 +13,5 @@ def _cleanup() -> None:
 # the fix for python3.7: https://github.com/python/cpython/pull/15706/files
 if sys.platform == 'win32':
     if sys.version_info < (3, 7):
-        subprocess._cleanup = _cleanup
-        subprocess._active = None
+        subprocess._cleanup = _cleanup  # type: ignore
+        subprocess._active = None  # type:ignore

nbclient/client.py

@@ -1,3 +1,5 @@
+from os import name as os_name
+from sys import version_info
 import atexit
 import collections
 import datetime
@@ -32,6 +34,11 @@
 from .output_widget import OutputWidget
 
 
+if os_name == "nt" and version_info.major == 3 and version_info.minor >= 8:
+    # patch c.f. https://github.com/tornadoweb/tornado/issues/2608#issuecomment-491489432
+    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())   # type: ignore
+
+
 def timestamp() -> str:
     return datetime.datetime.utcnow().isoformat() + 'Z'
 

tox.ini

@@ -1,13 +1,15 @@
 [tox]
 skipsdist = true
-envlist = py{36,37,38, 39}, flake8, mypy, dist, manifest, docs
+envlist = py{36,37,38, 39}, flake8, mypy, dist-{win, linux}, manifest, docs
+# requires =
+#     tox-factor
 
 [gh-actions]
 python =
     3.6: py36
     3.7: py37
     3.8: py38
-    3.9: py39, flake8, mypy, dist, manifest
+    3.9: py39, flake8, mypy, dist-{win, linux}, manifest
 
 # Linters
 [testenv:flake8]
@@ -39,13 +41,22 @@ commands =
     python -c 'import pathlib; print("documentation available under file://\{0\}".format(pathlib.Path(r"{toxworkdir}") / "docs_out" / "index.html"))'
 
 # Distro
-[testenv:dist]
+[testenv:dist-{win, linux}]
 skip_install = true
-# Have to use /bin/bash or the `*` will cause that argument to get quoted by the tox command line...
+platform =
+    win: win|msys
+    linux: linux|darwin
+allowlist_externals = 
+    win: powershell
+    linux: bash  
+
 commands =
     python setup.py sdist --dist-dir={distdir} bdist_wheel --dist-dir={distdir}
-    /bin/bash -c 'python -m pip install -U --force-reinstall {distdir}/nbclient*.whl'
-    /bin/bash -c 'python -m pip install -U --force-reinstall --no-deps {distdir}/nbclient*.tar.gz'
+    win: powershell Get-ChildItem -Path {distdir} -Filter nbclient*.whl | foreach \{python -m pip install -U --force-reinstall $_.FullName\}
+    win: powershell Get-ChildItem -Path {distdir} -Filter nbclient*.tar.gz | foreach \{python -m pip install -U --force-reinstall --no-deps $_.FullName\}
+    # Have to use /bin/bash or the `*` will cause that argument to get quoted by the tox command line...
+    linux: bash -c 'python -m pip install -U --force-reinstall {distdir}/nbclient*.whl'
+    linux: bash -c 'python -m pip install -U --force-reinstall --no-deps {distdir}/nbclient*.tar.gz'
 
 [testenv]
 # disable Python's hash randomization for tests that stringify dicts, etc