Switch uses of __import__ to importlib.get_module()

The Python docs for __import__ recommend using importlib.get_module().

https://docs.python.org/3/library/functions.html#__import__

> Note: This is an advanced function that is not needed in everyday
> Python programming, unlike importlib.import_module().

As importlib.get_module() uses the Python module cache and returns the
module, this also allows simplifying many module cache checks of use of
sys.modules.

importlib.get_module() has been available since Python 3.3.

1 files changed, 2 insertions, 2 deletions

diff --git a/sphinx/search/__init__.py b/sphinx/search/__init__.py
index 1b4f7ea59..22ba14d40 100644
--- a/sphinx/search/__init__.py
+++ b/sphinx/search/__init__.py
@@ -11,6 +11,7 @@ import html
 import pickle
 import re
 import warnings
+from importlib import import_module
 from os import path
 
 from docutils import nodes
@@ -278,8 +279,7 @@ class IndexBuilder:
             self.lang = SearchEnglish(options)  # type: SearchLanguage
         elif isinstance(lang_class, str):
             module, classname = lang_class.rsplit('.', 1)
-            lang_class = getattr(__import__(module, None, None, [classname]),
-                                 classname)
+            lang_class = getattr(import_module(module), classname)
             self.lang = lang_class(options)
         else:
             # it's directly a class (e.g. added by app.add_search_language)