py27+ syntax improvements

pre_commit/commands/autoupdate.py

@@ -50,8 +50,8 @@ def _update_repository(repo_config, runner):
     new_repo = Repository.create(new_config, runner.store)
 
     # See if any of our hooks were deleted with the new commits
-    hooks = set(hook_id for hook_id, _ in repo.hooks)
-    hooks_missing = hooks - (hooks & set(new_repo.manifest.hooks.keys()))
+    hooks = {hook_id for hook_id, _ in repo.hooks}
+    hooks_missing = hooks - (hooks & set(new_repo.manifest.hooks))
     if hooks_missing:
         raise RepositoryCannotBeUpdatedError(
             'Cannot update because the tip of master is missing these hooks:\n'

pre_commit/commands/run.py

@@ -19,7 +19,7 @@ logger = logging.getLogger('pre_commit')
 
 def _get_skips(environ):
     skips = environ.get('SKIP', '')
-    return set(skip.strip() for skip in skips.split(',') if skip.strip())
+    return {skip.strip() for skip in skips.split(',') if skip.strip()}
 
 
 def _hook_msg_start(hook, verbose):

pre_commit/git.py

@@ -88,7 +88,7 @@ def get_files_matching(all_file_list_strategy):
     def wrapper(include_expr, exclude_expr):
         include_regex = re.compile(include_expr)
         exclude_regex = re.compile(exclude_expr)
-        return set(
+        return {
             filename
             for filename in all_file_list_strategy()
             if (
@@ -96,7 +96,7 @@ def get_files_matching(all_file_list_strategy):
                 not exclude_regex.search(filename) and
                 os.path.lexists(filename)
             )
-        )
+        }
     return wrapper
 
 

pre_commit/manifest.py

@@ -21,4 +21,4 @@ class Manifest(object):
 
     @cached_property
     def hooks(self):
-        return dict((hook['id'], hook) for hook in self.manifest_contents)
+        return {hook['id']: hook for hook in self.manifest_contents}

pre_commit/repository.py

@@ -57,10 +57,10 @@ class Repository(object):
 
     @cached_property
     def languages(self):
-        return set(
+        return {
             (hook['language'], hook['language_version'])
             for _, hook in self.hooks
-        )
+        }
 
     @cached_property
     def additional_dependencies(self):

pre_commit/util.py

@@ -75,9 +75,9 @@ def no_git_env():
     # while running pre-commit hooks in submodules.
     # GIT_DIR: Causes git clone to clone wrong thing
     # GIT_INDEX_FILE: Causes 'error invalid object ...' during commit
-    return dict(
-        (k, v) for k, v in os.environ.items() if not k.startswith('GIT_')
-    )
+    return {
+        k: v for k, v in os.environ.items() if not k.startswith('GIT_')
+    }
 
 
 @contextlib.contextmanager
@@ -164,10 +164,10 @@ def cmd_output(*cmd, **kwargs):
 
     # py2/py3 on windows are more strict about the types here
     cmd = tuple(five.n(arg) for arg in cmd)
-    kwargs['env'] = dict(
-        (five.n(key), five.n(value))
+    kwargs['env'] = {
+        five.n(key): five.n(value)
         for key, value in kwargs.pop('env', {}).items()
-    ) or None
+    } or None
 
     try:
         cmd = parse_shebang.normalize_cmd(cmd)