Add support for Python 3.8

.circleci/config.yml

@@ -113,173 +113,173 @@ eth2_fixtures: &eth2_fixtures
           - ./eth2-fixtures
         key: cache-v3-{{ arch }}-{{ .Environment.CIRCLE_JOB }}-{{ checksum "setup.py" }}-{{ checksum "tox.ini" }}-{{ checksum "./.circleci/get_eth2_fixtures.sh" }}-{{ checksum "./.circleci/build_geth.sh" }}
 jobs:
-  py36-lint:
+  py38-lint:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-lint
+          TOXENV: py38-lint
   py37-lint:
     <<: *common
     docker:
       - image: circleci/python:3.7
         environment:
           TOXENV: py37-lint
-  py36-lint-eth2:
+  py38-lint-eth2:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-lint-eth2
+          TOXENV: py38-lint-eth2
   py37-lint-eth2:
     <<: *common
     docker:
       - image: circleci/python:3.7
         environment:
           TOXENV: py37-lint-eth2
 
-  py36-docs:
+  py38-docs:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-docs
+          TOXENV: py38-docs
 
-  py36-rpc-state-byzantium:
+  py38-rpc-state-byzantium:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-byzantium
-  py36-rpc-state-constantinople:
+          TOXENV: py38-rpc-state-byzantium
+  py38-rpc-state-constantinople:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-constantinople
-  py36-rpc-state-frontier:
+          TOXENV: py38-rpc-state-constantinople
+  py38-rpc-state-frontier:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-frontier
-  py36-rpc-state-homestead:
+          TOXENV: py38-rpc-state-frontier
+  py38-rpc-state-homestead:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-homestead
-  py36-rpc-state-istanbul:
+          TOXENV: py38-rpc-state-homestead
+  py38-rpc-state-istanbul:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-istanbul
-  py36-rpc-state-petersburg:
+          TOXENV: py38-rpc-state-istanbul
+  py38-rpc-state-petersburg:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-petersburg
+          TOXENV: py38-rpc-state-petersburg
 
-  py36-rpc-state-tangerine_whistle:
+  py38-rpc-state-tangerine_whistle:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-tangerine_whistle
-  py36-rpc-state-spurious_dragon:
+          TOXENV: py38-rpc-state-tangerine_whistle
+  py38-rpc-state-spurious_dragon:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-state-spurious_dragon
-  py36-rpc-blockchain:
+          TOXENV: py38-rpc-state-spurious_dragon
+  py38-rpc-blockchain:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-rpc-blockchain
+          TOXENV: py38-rpc-blockchain
 
-  py36-eth1-core:
+  py38-eth1-core:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-eth1-core
-  py36-integration:
+          TOXENV: py38-eth1-core
+  py38-integration:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-integration
-  py36-lightchain_integration:
+          TOXENV: py38-integration
+  py38-lightchain_integration:
     <<: *geth_steps
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-lightchain_integration
+          TOXENV: py38-lightchain_integration
           GETH_VERSION: v1.8.22
-  py36-long_run_integration:
+  py38-long_run_integration:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-long_run_integration
-  py36-p2p:
+          TOXENV: py38-long_run_integration
+  py38-p2p:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-p2p
-  py36-p2p-trio:
+          TOXENV: py38-p2p
+  py38-p2p-trio:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-p2p-trio
-  py36-eth2-core:
+          TOXENV: py38-p2p-trio
+  py38-eth2-core:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-eth2-core
-  py36-eth2-utils:
+          TOXENV: py38-eth2-core
+  py38-eth2-utils:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-eth2-utils
-  py36-eth2-fixtures:
+          TOXENV: py38-eth2-utils
+  py38-eth2-fixtures:
     <<: *eth2_fixtures
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-eth2-fixtures
-  py36-eth2-integration:
+          TOXENV: py38-eth2-fixtures
+  py38-eth2-integration:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-eth2-integration
-  py36-wheel-cli:
+          TOXENV: py38-eth2-integration
+  py38-wheel-cli:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-wheel-cli
-  py36-eth1-components:
+          TOXENV: py38-wheel-cli
+  py38-eth1-components:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-eth1-components
-  py36-eth2-trio:
+          TOXENV: py38-eth1-components
+  py38-eth2-trio:
     <<: *common
     docker:
-      - image: circleci/python:3.6
+      - image: circleci/python:3.8
         environment:
-          TOXENV: py36-eth2-trio
+          TOXENV: py38-eth2-trio
 
   py37-rpc-state-quadratic:
     <<: *common
@@ -398,16 +398,16 @@ workflows:
   test:
     jobs:
       # These tests are long, so should be started first to optimize for total suite run time
-      - py36-integration
-      - py36-wheel-cli
+      - py38-integration
+      - py38-wheel-cli
       - py37-wheel-cli
-      - py36-long_run_integration
+      - py38-long_run_integration
       - py37-rpc-state-sstore
-      - py36-eth2-core
+      - py38-eth2-core
       - py37-eth2-core
       - py37-libp2p
 
-      - py36-docs
+      - py38-docs
 
       - py37-eth1-core
       - py37-p2p
@@ -422,28 +422,28 @@ workflows:
       - py37-rpc-state-quadratic
       - py37-rpc-state-zero_knowledge
 
-      - py36-rpc-state-byzantium
-      - py36-rpc-state-constantinople
-      - py36-rpc-state-frontier
-      - py36-rpc-state-homestead
-      - py36-rpc-state-petersburg
-      - py36-rpc-state-spurious_dragon
-      - py36-rpc-state-tangerine_whistle
-      - py36-rpc-blockchain
+      - py38-rpc-state-byzantium
+      - py38-rpc-state-constantinople
+      - py38-rpc-state-frontier
+      - py38-rpc-state-homestead
+      - py38-rpc-state-petersburg
+      - py38-rpc-state-spurious_dragon
+      - py38-rpc-state-tangerine_whistle
+      - py38-rpc-blockchain
 
-      - py36-eth1-core
-      - py36-p2p
-      - py36-p2p-trio
-      - py36-eth2-utils
-      - py36-eth2-fixtures
-      - py36-eth2-integration
-      - py36-eth1-components
-      - py36-eth2-trio
+      - py38-eth1-core
+      - py38-p2p
+      - py38-p2p-trio
+      - py38-eth2-utils
+      - py38-eth2-fixtures
+      - py38-eth2-integration
+      - py38-eth1-components
+      - py38-eth2-trio
 
-      - py36-lightchain_integration
+      - py38-lightchain_integration
 
-      - py36-lint
-      - py36-lint-eth2
+      - py38-lint
+      - py38-lint-eth2
       - py37-lint
       - py37-lint-eth2
 

.readthedocs.yml

@@ -3,7 +3,7 @@ version: 2
 build:
   image: latest
 python:
-  version: 3.6
+  version: 3.7
   install:
     - method: pip
       path: .

docs/guides/quickstart.rst

@@ -12,8 +12,8 @@ To develop on top of Trinity or to contribute to the project, check out the
 Installing on Ubuntu
 --------------------
 
-Trinity requires Python 3.6 as well as some tools to compile its dependencies. On Ubuntu, the
-``python3.6-dev`` package contains everything we need. Run the following command to install it.
+Trinity requires Python 3.7 as well as some tools to compile its dependencies. On Ubuntu, the
+``python3.7-dev`` package contains everything we need. Run the following command to install it.
 
 .. code:: sh
 

newsfragments/1675.removal.rst

@@ -0,0 +1 @@
+Drop support for Python 3.6 making Python 3.7 the minimal supported Python version.

p2p/_utils.py

@@ -1,5 +1,5 @@
 import collections
-from typing import Hashable, Sequence, Tuple, TypeVar
+from typing import Hashable, Sequence, Tuple, TypeVar, AsyncGenerator, Any
 
 import rlp
 
@@ -93,3 +93,18 @@ def duplicates(elements: Sequence[TValue]) -> Tuple[TValue, ...]:
         collections.Counter(elements).items()
         if count > 1
     )
+
+
+TCo = TypeVar('TCo')
+TContra = TypeVar('TContra')
+
+
+class aclosing:
+    def __init__(self, aiter: AsyncGenerator[TCo, TContra]) -> None:
+        self._aiter = aiter
+
+    async def __aenter__(self) -> AsyncGenerator[TCo, TContra]:
+        return self._aiter
+
+    async def __aexit__(self, *args: Any) -> None:
+        await self._aiter.aclose()

p2p/behaviors.py

@@ -1,9 +1,8 @@
+import contextlib
 from typing import (
     AsyncIterator,
 )
 
-from async_generator import asynccontextmanager
-
 from eth_utils import ValidationError
 
 from p2p.abc import (
@@ -36,7 +35,7 @@ def should_apply_to(self, connection: 'ConnectionAPI') -> bool:
         # mypy bug: https://github.com/python/mypy/issues/708
         return self.qualifier(connection, self.logic)  # type: ignore
 
-    @asynccontextmanager
+    @contextlib.asynccontextmanager
     async def apply(self, connection: ConnectionAPI) -> AsyncIterator[None]:
         if self._applied_to is not None:
             raise ValidationError(