Drop Python 3.6 support (#29978)

.coveragerc

@@ -5,7 +5,6 @@ omit =
     homeassistant/__main__.py
     homeassistant/helpers/signal.py
     homeassistant/helpers/typing.py
-    homeassistant/monkey_patch.py
     homeassistant/scripts/*.py
     homeassistant/util/async.py
 

.readthedocs.yml

@@ -4,7 +4,7 @@ build:
   image: latest
 
 python:
-  version: 3.6
+  version: 3.7
   setup_py_install: true
 
 requirements_file: requirements_docs.txt

.travis.yml

@@ -14,15 +14,13 @@ addons:
 matrix:
   fast_finish: true
   include:
-    - python: "3.6.1"
+    - python: "3.7.0"
       env: TOXENV=lint
-    - python: "3.6.1"
+    - python: "3.7.0"
       env: TOXENV=pylint PYLINT_ARGS=--jobs=0 TRAVIS_WAIT=30
-    - python: "3.6.1"
+    - python: "3.7.0"
       env: TOXENV=typing
-    - python: "3.6.1"
-      env: TOXENV=py36
-    - python: "3.7"
+    - python: "3.7.0"
       env: TOXENV=py37
 
 cache:

azure-pipelines-ci.yml

@@ -14,8 +14,6 @@ pr:
 
 resources:
   containers:
-  - container: 36
-    image: homeassistant/ci-azure:3.6
   - container: 37
     image: homeassistant/ci-azure:3.7
   repositories:
@@ -25,7 +23,7 @@ resources:
       endpoint: 'home-assistant'
 variables:
   - name: PythonMain
-    value: '36'
+    value: '37'
   - group: codecov
 
 stages:
@@ -108,8 +106,6 @@ stages:
     strategy:
       maxParallel: 3
       matrix:
-        Python36:
-          python.container: '36'
         Python37:
           python.container: '37'
     container: $[ variables['python.container'] ]

homeassistant/__main__.py

@@ -1,5 +1,6 @@
 """Start Home Assistant."""
 import argparse
+import asyncio
 import os
 import platform
 import subprocess
@@ -7,7 +8,6 @@ import sys
 import threading
 from typing import TYPE_CHECKING, Any, Dict, List
 
-from homeassistant import monkey_patch
 from homeassistant.const import REQUIRED_PYTHON_VER, RESTART_EXIT_CODE, __version__
 
 if TYPE_CHECKING:
@@ -16,7 +16,6 @@ if TYPE_CHECKING:
 
 def set_loop() -> None:
     """Attempt to use different loop."""
-    import asyncio
     from asyncio.events import BaseDefaultEventLoopPolicy
 
     if sys.platform == "win32":
@@ -345,11 +344,6 @@ def main() -> int:
     """Start Home Assistant."""
     validate_python()
 
-    monkey_patch_needed = sys.version_info[:3] < (3, 6, 3)
-    if monkey_patch_needed and os.environ.get("HASS_NO_MONKEY") != "1":
-        monkey_patch.disable_c_asyncio()
-        monkey_patch.patch_weakref_tasks()
-
     set_loop()
 
     # Run a simple daemon runner process on Windows to handle restarts
@@ -383,13 +377,11 @@ def main() -> int:
     if args.pid_file:
         write_pid(args.pid_file)
 
-    from homeassistant.util.async_ import asyncio_run
-
-    exit_code = asyncio_run(setup_and_run_hass(config_dir, args))
+    exit_code = asyncio.run(setup_and_run_hass(config_dir, args))
     if exit_code == RESTART_EXIT_CODE and not args.runner:
         try_to_restart()
 
-    return exit_code  # type: ignore
+    return exit_code
 
 
 if __name__ == "__main__":

homeassistant/const.py

@@ -4,10 +4,10 @@ MINOR_VERSION = 104
 PATCH_VERSION = "0.dev0"
 __short_version__ = "{}.{}".format(MAJOR_VERSION, MINOR_VERSION)
 __version__ = "{}.{}".format(__short_version__, PATCH_VERSION)
-REQUIRED_PYTHON_VER = (3, 6, 1)
+REQUIRED_PYTHON_VER = (3, 7, 0)
 # Truthy date string triggers showing related deprecation warning messages.
-REQUIRED_NEXT_PYTHON_VER = (3, 7, 0)
-REQUIRED_NEXT_PYTHON_DATE = "December 15, 2019"
+REQUIRED_NEXT_PYTHON_VER = (3, 8, 0)
+REQUIRED_NEXT_PYTHON_DATE = ""
 
 # Format for platform files
 PLATFORM_FORMAT = "{platform}.{domain}"

homeassistant/monkey_patch.py

@@ -1,73 +0,0 @@
-"""Monkey patch Python to work around issues causing segfaults.
-
-Under heavy threading operations that schedule calls into
-the asyncio event loop, Task objects are created. Due to
-a bug in Python, GC may have an issue when switching between
-the threads and objects with __del__ (which various components
-in HASS have).
-
-This monkey-patch removes the weakref.Weakset, and replaces it
-with an object that ignores the only call utilizing it (the
-Task.__init__ which calls _all_tasks.add(self)). It also removes
-the __del__ which could trigger the future objects __del__ at
-unpredictable times.
-
-The side-effect of this manipulation of the Task is that
-Task.all_tasks() is no longer accurate, and there will be no
-warning emitted if a Task is GC'd while in use.
-
-Related Python bugs:
- - https://bugs.python.org/issue26617
-"""
-import sys
-from typing import Any
-
-
-def patch_weakref_tasks() -> None:
-    """Replace weakref.WeakSet to address Python 3 bug."""
-    # pylint: disable=no-self-use, protected-access
-    import asyncio.tasks
-
-    class IgnoreCalls:
-        """Ignore add calls."""
-
-        def add(self, other: Any) -> None:
-            """No-op add."""
-            return
-
-    asyncio.tasks.Task._all_tasks = IgnoreCalls()  # type: ignore
-    try:
-        del asyncio.tasks.Task.__del__
-    except:  # noqa: E722 pylint: disable=bare-except
-        pass
-
-
-def disable_c_asyncio() -> None:
-    """Disable using C implementation of asyncio.
-
-    Required to be able to apply the weakref monkey patch.
-
-    Requires Python 3.6+.
-    """
-
-    class AsyncioImportFinder:
-        """Finder that blocks C version of asyncio being loaded."""
-
-        PATH_TRIGGER = "_asyncio"
-
-        def __init__(self, path_entry: str) -> None:
-            if path_entry != self.PATH_TRIGGER:
-                raise ImportError()
-
-        def find_module(self, fullname: str, path: Any = None) -> None:
-            """Find a module."""
-            if fullname == self.PATH_TRIGGER:
-                raise ModuleNotFoundError()
-
-    sys.path_hooks.append(AsyncioImportFinder)
-    sys.path.insert(0, AsyncioImportFinder.PATH_TRIGGER)
-
-    try:
-        import _asyncio  # noqa: F401
-    except ImportError:
-        pass

homeassistant/package_constraints.txt

@@ -7,7 +7,6 @@ async_timeout==3.0.1
 attrs==19.3.0
 bcrypt==3.1.7
 certifi>=2019.11.28
-contextvars==2.4;python_version<"3.7"
 cryptography==2.8
 defusedxml==0.6.0
 distro==1.4.0
@@ -29,7 +28,7 @@ zeroconf==0.24.0
 
 pycryptodome>=3.6.6
 
-# Breaks Python 3.6 and is not needed for our supported Python versions
+# Not needed for our supported Python versions
 enum34==1000000000.0.0
 
 # This is a old unmaintained library and is replaced with pycryptodome

homeassistant/util/async_.py

@@ -1,33 +1,14 @@
 """Asyncio backports for Python 3.6 compatibility."""
-import asyncio
 from asyncio import coroutines, ensure_future
 from asyncio.events import AbstractEventLoop
 import concurrent.futures
 import logging
 import threading
-from typing import Any, Awaitable, Callable, Coroutine, TypeVar
+from typing import Any, Callable, Coroutine
 
 _LOGGER = logging.getLogger(__name__)
 
 
-try:
-    # pylint: disable=invalid-name
-    asyncio_run = asyncio.run  # type: ignore
-except AttributeError:
-    _T = TypeVar("_T")
-
-    def asyncio_run(main: Awaitable[_T], *, debug: bool = False) -> _T:
-        """Minimal re-implementation of asyncio.run (since 3.7)."""
-        loop = asyncio.new_event_loop()
-        asyncio.set_event_loop(loop)
-        loop.set_debug(debug)
-        try:
-            return loop.run_until_complete(main)
-        finally:
-            asyncio.set_event_loop(None)
-            loop.close()
-
-
 def fire_coroutine_threadsafe(coro: Coroutine, loop: AbstractEventLoop) -> None:
     """Submit a coroutine object to a given event loop.
 

pyproject.toml

@@ -1,3 +1,3 @@
 [tool.black]
-target-version = ["py36", "py37", "py38"]
+target-version = ["py37", "py38"]
 exclude = 'generated'

requirements_all.txt

@@ -5,7 +5,6 @@ async_timeout==3.0.1
 attrs==19.3.0
 bcrypt==3.1.7
 certifi>=2019.11.28
-contextvars==2.4;python_version<"3.7"
 importlib-metadata==0.23
 jinja2>=2.10.3
 PyJWT==1.7.1

script/gen_requirements_all.py

@@ -58,7 +58,7 @@ CONSTRAINT_PATH = os.path.join(
 CONSTRAINT_BASE = """
 pycryptodome>=3.6.6
 
-# Breaks Python 3.6 and is not needed for our supported Python versions
+# Not needed for our supported Python versions
 enum34==1000000000.0.0
 
 # This is a old unmaintained library and is replaced with pycryptodome

setup.cfg

@@ -11,7 +11,6 @@ classifier =
     Intended Audience :: Developers
     License :: OSI Approved :: Apache Software License
     Operating System :: OS Independent
-    Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Topic :: Home Automation
 
@@ -57,7 +56,7 @@ forced_separate = tests
 combine_as_imports = true
 
 [mypy]
-python_version = 3.6
+python_version = 3.7
 ignore_errors = true
 follow_imports = silent
 ignore_missing_imports = true
@@ -65,7 +64,7 @@ warn_incomplete_stub = true
 warn_redundant_casts = true
 warn_unused_configs = true
 
-[mypy-homeassistant.bootstrap,homeassistant.components,homeassistant.config_entries,homeassistant.config,homeassistant.const,homeassistant.core,homeassistant.data_entry_flow,homeassistant.exceptions,homeassistant.loader,homeassistant.__main__,homeassistant.monkey_patch,homeassistant.requirements,homeassistant.setup,homeassistant.util,homeassistant.auth.*,homeassistant.components.automation.*,homeassistant.components.binary_sensor.*,homeassistant.components.calendar.*,homeassistant.components.cover.*,homeassistant.components.device_automation.*,homeassistant.components.frontend.*,homeassistant.components.geo_location.*,homeassistant.components.group.*,homeassistant.components.history.*,homeassistant.components.http.*,homeassistant.components.image_processing.*,homeassistant.components.integration.*,homeassistant.components.light.*,homeassistant.components.lock.*,homeassistant.components.mailbox.*,homeassistant.components.media_player.*,homeassistant.components.notify.*,homeassistant.components.persistent_notification.*,homeassistant.components.proximity.*,homeassistant.components.remote.*,homeassistant.components.scene.*,homeassistant.components.sensor.*,homeassistant.components.sun.*,homeassistant.components.switch.*,homeassistant.components.systemmonitor.*,homeassistant.components.tts.*,homeassistant.components.vacuum.*,homeassistant.components.water_heater.*,homeassistant.components.weather.*,homeassistant.components.websocket_api.*,homeassistant.components.zone.*,homeassistant.helpers.*,homeassistant.scripts.*,homeassistant.util.*]
+[mypy-homeassistant.bootstrap,homeassistant.components,homeassistant.config_entries,homeassistant.config,homeassistant.const,homeassistant.core,homeassistant.data_entry_flow,homeassistant.exceptions,homeassistant.loader,homeassistant.__main__,homeassistant.requirements,homeassistant.setup,homeassistant.util,homeassistant.auth.*,homeassistant.components.automation.*,homeassistant.components.binary_sensor.*,homeassistant.components.calendar.*,homeassistant.components.cover.*,homeassistant.components.device_automation.*,homeassistant.components.frontend.*,homeassistant.components.geo_location.*,homeassistant.components.group.*,homeassistant.components.history.*,homeassistant.components.http.*,homeassistant.components.image_processing.*,homeassistant.components.integration.*,homeassistant.components.light.*,homeassistant.components.lock.*,homeassistant.components.mailbox.*,homeassistant.components.media_player.*,homeassistant.components.notify.*,homeassistant.components.persistent_notification.*,homeassistant.components.proximity.*,homeassistant.components.remote.*,homeassistant.components.scene.*,homeassistant.components.sensor.*,homeassistant.components.sun.*,homeassistant.components.switch.*,homeassistant.components.systemmonitor.*,homeassistant.components.tts.*,homeassistant.components.vacuum.*,homeassistant.components.water_heater.*,homeassistant.components.weather.*,homeassistant.components.websocket_api.*,homeassistant.components.zone.*,homeassistant.helpers.*,homeassistant.scripts.*,homeassistant.util.*]
 ignore_errors = false
 check_untyped_defs = true
 disallow_incomplete_defs = true

setup.py

@@ -38,7 +38,6 @@ REQUIRES = [
     "attrs==19.3.0",
     "bcrypt==3.1.7",
     "certifi>=2019.11.28",
-    'contextvars==2.4;python_version<"3.7"',
     "importlib-metadata==0.23",
     "jinja2>=2.10.3",
     "PyJWT==1.7.1",

tests/util/test_async.py

@@ -1,6 +1,5 @@
 """Tests for async util methods from Python source."""
 import asyncio
-import sys
 from unittest import TestCase
 from unittest.mock import MagicMock, patch
 
@@ -112,11 +111,7 @@ class RunThreadsafeTests(TestCase):
         """Wait 0.05 second and return a + b."""
         yield from asyncio.sleep(0.05, loop=self.loop)
         if cancel:
-            if sys.version_info[:2] >= (3, 7):
-                current_task = asyncio.current_task
-            else:
-                current_task = asyncio.tasks.Task.current_task
-            current_task(self.loop).cancel()
+            asyncio.current_task(self.loop).cancel()
             yield
         return self.add_callback(a, b, fail, invalid)