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_project_tests.py b/run_project_tests.py
index b6879ee..b14e817 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -1352,7 +1352,7 @@ if __name__ == '__main__':
             except UnicodeError:
                 print(l.encode('ascii', errors='replace').decode(), '\n')
     for name, dirs, _ in all_tests:
-        dir_names = list(set(x.path.name for x in dirs))
+        dir_names = list({x.path.name for x in dirs})
         for k, g in itertools.groupby(dir_names, key=lambda x: x.split()[0]):
             tests = list(g)
             if len(tests) != 1: