Use importlib.metadata directly in python3.8+

azure-pipelines.yml

@@ -36,7 +36,7 @@ jobs:
       displayName: install swift
 - template: job--python-tox.yml@asottile
   parameters:
-    toxenvs: [pypy, pypy3, py27, py36, py37]
+    toxenvs: [pypy, pypy3, py27, py36, py37, py38]
     os: linux
     pre_test:
     - task: UseRubyVersion@0

pre_commit/constants.py

@@ -1,7 +1,12 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import importlib_metadata  # TODO: importlib.metadata py38?
+import sys
+
+if sys.version_info < (3, 8):  # pragma: no cover (<PY38)
+    import importlib_metadata
+else:  # pragma: no cover (PY38+)
+    import importlib.metadata as importlib_metadata
 
 CONFIG_FILE = '.pre-commit-config.yaml'
 MANIFEST_FILE = '.pre-commit-hooks.yaml'

setup.cfg

@@ -14,10 +14,10 @@ classifiers =
     Programming Language :: Python :: 2
     Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.4
     Programming Language :: Python :: 3.5
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: Implementation :: PyPy
 
@@ -27,15 +27,15 @@ install_requires =
     aspy.yaml
     cfgv>=2.0.0
     identify>=1.0.0
-    importlib-metadata
     nodeenv>=0.11.1
     pyyaml
     six
     toml
     virtualenv>=15.2
-    futures; python_version<"3.2"
-    importlib-resources; python_version<"3.7"
-python_requires = >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*
+    futures;python_version<"3.2"
+    importlib-metadata;python_version<"3.8"
+    importlib-resources;python_version<"3.7"
+python_requires = >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*
 
 [options.entry_points]
 console_scripts =