Use loop.create_task with interact() (#270)

* Use loop.create_task with interact()

Passing coroutines directly to asyncio.wait is deprecated since
Python 3.8, as it leads to confusing behavior:
    https://docs.python.org/3.10/library/asyncio-task.html#asyncio-example-wait-coroutine
In Python 3.11, wait() no longer accepts coroutines and
must be given Tasks.

* Put task handling in an async function and use asyncio.run()

* Drop Python 3.6 support and switch to 3.7+ API

* setup.py: Remove Minimal Python version sanity check

Author: encukou

.github/workflows/python-package.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10']
+        python-version: ['3.7', '3.8', '3.9', '3.10']
 
     steps:
     - uses: actions/checkout@v2

jupyter_console/ptshell.py

@@ -649,31 +649,31 @@ async def interact(self, loop=None, display_banner=None):
                 if code:
                     self.run_cell(code, store_history=True)
 
+    async def _main_task(self):
+        loop = asyncio.get_running_loop()
+        tasks = [asyncio.create_task(self.interact(loop=loop))]
+
+        if self.include_other_output:
+            # only poll the iopub channel asynchronously if we
+            # wish to include external content
+            tasks.append(asyncio.create_task(self.handle_external_iopub(loop=loop)))
+
+        _, pending = await asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)
+
+        for task in pending:
+            task.cancel()
+        try:
+            await asyncio.gather(*pending)
+        except asyncio.CancelledError:
+            pass
+
     def mainloop(self):
         self.keepkernel = not self.own_kernel
-        loop = asyncio.get_event_loop()
         # An extra layer of protection in case someone mashing Ctrl-C breaks
         # out of our internal code.
         while True:
             try:
-                tasks = [self.interact(loop=loop)]
-
-                if self.include_other_output:
-                    # only poll the iopub channel asynchronously if we
-                    # wish to include external content
-                    tasks.append(self.handle_external_iopub(loop=loop))
-
-                main_task = asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)
-                _, pending = loop.run_until_complete(main_task)
-
-                for task in pending:
-                    task.cancel()
-                try:
-                    loop.run_until_complete(asyncio.gather(*pending))
-                except asyncio.CancelledError:
-                    pass
-                loop.stop()
-                loop.close()
+                asyncio.run(self._main_task())
                 break
             except KeyboardInterrupt:
                 print("\nKeyboardInterrupt escaped interact()\n")

mypy.ini

@@ -1,4 +1,4 @@
 [mypy]
-python_version = 3.6
+python_version = 3.7
 ignore_missing_imports = True
 follow_imports = silent

setup.py

@@ -9,46 +9,6 @@
 # the name of the project
 name = 'jupyter_console'
 
-#-----------------------------------------------------------------------------
-# Minimal Python version sanity check
-#-----------------------------------------------------------------------------
-
-import sys
-
-
-if sys.version_info < (3, 6):
-    pip_message = 'This may be due to an out of date pip. Make sure you have pip >= 9.0.1.'
-    try:
-        import pip
-        pip_version = tuple([int(x) for x in pip.__version__.split('.')[:3]])
-        if pip_version < (9, 0, 1) :
-            pip_message = 'Your pip version is out of date, please install pip >= 9.0.1. '\
-            'pip {} detected.'.format(pip.__version__)
-        else:
-            # pip is new enough - it must be something else
-            pip_message = ''
-    except Exception:
-        pass
-
-
-    error = """
-Jupyter_Console 6.2+ supports Python 3.6 and above.
-When using Python 2.7, please install and older version of Jupyter Console
-Python 3.3 and 3.4 were supported up to Jupyter Console 5.x.
-Python 3.5 was supported up to Jupyter Console 6.1.0.
-
-Python {py} detected.
-{pip}
-""".format(py=sys.version_info, pip=pip_message )
-
-    print(error, file=sys.stderr)
-    sys.exit(1)
-
-
-#-----------------------------------------------------------------------------
-# get on with it
-#-----------------------------------------------------------------------------
-
 import os
 
 from setuptools import setup
@@ -82,7 +42,6 @@
         'License :: OSI Approved :: BSD License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
@@ -97,7 +56,7 @@
     extras_require={
         'test:sys_platform != "win32"': ['pexpect'],
     },
-    python_requires='>=3.6',
+    python_requires='>=3.7',
     entry_points={
         'console_scripts': [
             'jupyter-console = jupyter_console.app:main',