Sort imports with isort

Keep imports alphabetically sorted and their order homogeneous across
Python source files.

The isort project has more feature and is more active than the
flake8-import-order plugin.

Most issues caught were simply import ordering from the same module.
Where imports were purposefully placed out of order, tag with
isort:skip.

1 files changed, 3 insertions, 3 deletions

diff --git a/sphinx/util/docfields.py b/sphinx/util/docfields.py
index c07bc7f66..404bb127f 100644
--- a/sphinx/util/docfields.py
+++ b/sphinx/util/docfields.py
@@ -10,8 +10,7 @@
 """
 
 import warnings
-from typing import Any, Dict, List, Tuple, Union
-from typing import cast
+from typing import Any, Dict, List, Tuple, Union, cast
 
 from docutils import nodes
 from docutils.nodes import Node
@@ -23,8 +22,9 @@ from sphinx.util.typing import TextlikeNode
 if False:
     # For type annotation
     from typing import Type  # for python3.5.1
-    from sphinx.environment import BuildEnvironment
+
     from sphinx.directive import ObjectDescription
+    from sphinx.environment import BuildEnvironment
 
 
 def _is_single_paragraph(node: nodes.field_body) -> bool: