fix all b904s (#2501)

[etc/vim.git] / src / blackd / __init__.py

diff --git a/src/blackd/__init__.py b/src/blackd/__init__.py
index 10b616894dabbaa566691f42bcfa5017c8dd6eef..d062303fd10d4f3190de861cfb5a4ddd42f2ac0a 100644 (file)
--- a/src/blackd/__init__.py
+++ b/src/blackd/__init__.py
@@ -1,6 +1,5 @@
 import asyncio
 import logging
-import sys
 from concurrent.futures import Executor, ProcessPoolExecutor
 from datetime import datetime
 from functools import partial
@@ -11,25 +10,16 @@ try:
     from aiohttp import web
     import aiohttp_cors
 except ImportError as ie:
-    print(
+    raise ImportError(
         f"aiohttp dependency is not installed: {ie}. "
         + "Please re-install black with the '[d]' extra install "
-        + "to obtain aiohttp_cors: `pip install black[d]`",
-        file=sys.stderr,
-    )
-    sys.exit(-1)
+        + "to obtain aiohttp_cors: `pip install black[d]`"
+    ) from None
 
 import black
+from black.concurrency import maybe_install_uvloop
 import click
 
-# If our environment has uvloop installed lets use it
-try:
-    import uvloop
-
-    uvloop.install()
-except ImportError:
-    pass
-
 from _black_version import version as __version__
 
 # This is used internally by tests to shut down the server prematurely
@@ -205,11 +195,12 @@ def parse_python_variant_header(value: str) -> Tuple[bool, Set[black.TargetVersi
                     raise InvalidVariantHeader(f"3.{minor} is not supported")
                 versions.add(black.TargetVersion[version_str])
             except (KeyError, ValueError):
-                raise InvalidVariantHeader("expected e.g. '3.7', 'py3.5'")
+                raise InvalidVariantHeader("expected e.g. '3.7', 'py3.5'") from None
         return False, versions
 
 
 def patched_main() -> None:
+    maybe_install_uvloop()
     freeze_support()
     black.patch_click()
     main()