Python-3-only clean ups discovered by pyupgrade

https://github.com/asottile/pyupgrade

> A tool to automatically upgrade syntax for newer versions of the
> language.

- Drop u str prefix
- Drop base object inheritance
- Drop args to super()
- Use set literals
- Use dict comprehension
- Use set comprehension

2 files changed, 6 insertions, 7 deletions

diff --git a/sphinx/search/__init__.py b/sphinx/search/__init__.py
index dd30b5045..868b0e489 100644
--- a/sphinx/search/__init__.py
+++ b/sphinx/search/__init__.py
@@ -310,9 +310,9 @@ class IndexBuilder:
             rv = {}
             for k, v in mapping.items():
                 if isinstance(v, int):
-                    rv[k] = set([index2fn[v]])
+                    rv[k] = {index2fn[v]}
                 else:
-                    rv[k] = set(index2fn[i] for i in v)
+                    rv[k] = {index2fn[i] for i in v}
             return rv
 
         self._mapping = load_terms(frozen['terms'])
@@ -381,12 +381,11 @@ class IndexBuilder:
         """Create a usable data structure for serializing."""
         docnames, titles = zip(*sorted(self._titles.items()))
         filenames = [self._filenames.get(docname) for docname in docnames]
-        fn2index = dict((f, i) for (i, f) in enumerate(docnames))
+        fn2index = {f: i for (i, f) in enumerate(docnames)}
         terms, title_terms = self.get_terms(fn2index)
 
         objects = self.get_objects(fn2index)  # populates _objtypes
-        objtypes = dict((v, k[0] + ':' + k[1])
-                        for (k, v) in self._objtypes.items())
+        objtypes = {v: k[0] + ':' + k[1] for (k, v) in self._objtypes.items()}
         objnames = self._objnames
         return dict(docnames=docnames, filenames=filenames, titles=titles, terms=terms,
                     objects=objects, objtypes=objtypes, objnames=objnames,
diff --git a/sphinx/search/ja.py b/sphinx/search/ja.py
index 814296f79..0c11af74d 100644
--- a/sphinx/search/ja.py
+++ b/sphinx/search/ja.py
@@ -155,14 +155,14 @@ class JanomeSplitter(BaseSplitter):
 
 
 class DefaultSplitter(BaseSplitter):
-    patterns_ = dict([(re.compile(pattern), value) for pattern, value in {
+    patterns_ = {re.compile(pattern): value for pattern, value in {
         '[一二三四五六七八九十百千万億兆]': 'M',
         '[一-龠々〆ヵヶ]': 'H',
         '[ぁ-ん]': 'I',
         '[ァ-ヴーｱ-ﾝﾞｰ]': 'K',
         '[a-zA-Zａ-ｚＡ-Ｚ]': 'A',
         '[0-9０-９]': 'N',
-    }.items()])
+    }.items()}
     BIAS__ = -332
     BC1__ = {'HH': 6, 'II': 2461, 'KH': 406, 'OH': -1378}
     BC2__ = {'AA': -3267, 'AI': 2744, 'AN': -878, 'HH': -4070, 'HM': -1711,