various python neatness cleanups

All changes were created by running

"pyupgrade --py3-only --keep-percent-format"

and committing the results. I have not touched string formatting for
now.

- use set literals
- simplify .format() parameter naming
- remove __future__
- remove default "r" mode for open()
- use OSError rather than compatibility aliases
- remove stray parentheses in function(generator) scopes

1 files changed, 1 insertions, 1 deletions

diff --git a/run_tests.py b/run_tests.py
index 1e01aa9..85434e4 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -190,7 +190,7 @@ def find_vcxproj_with_target(builddir, target):
     for _, _, files in os.walk(builddir):
         for f in fnmatch.filter(files, '*.vcxproj'):
             f = os.path.join(builddir, f)
-            with open(f, 'r', encoding='utf-8') as o:
+            with open(f, encoding='utf-8') as o:
                 if re.search(p, o.read(), flags=re.MULTILINE):
                     return f
     raise RuntimeError('No vcxproj matching {!r} in {!r}'.format(p, builddir))