Fix a few typos and style in checkdeps

tools/checkdeps/rules.py

 # Copyright 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Base classes to represent dependency rules, used by checkdeps.py"""
 
 
 import os
 import re
 
@@ skipping 17 matching lines @@
     self._source = source
 
   def __str__(self):
     return '"%s%s" from %s.' % (self.allow, self._dir, self._source)
 
   def AsDependencyTuple(self):
     """Returns a tuple (allow, dependent dir, dependee dir) for this rule,
     which is fully self-sufficient to answer the question whether the dependent
     is allowed to depend on the dependee, without knowing the external
     context."""
-    return (self.allow, self._dependent_dir or '.', self._dir or '.')
+    return self.allow, self._dependent_dir or '.', self._dir or '.'
 
   def ParentOrMatch(self, other):
     """Returns true if the input string is an exact match or is a parent
     of the current rule. For example, the input "foo" would match "foo/bar"."""
     return self._dir == other or self._dir.startswith(other + '/')
 
   def ChildOrMatch(self, other):
     """Returns true if the input string would be covered by this rule. For
     example, the input "foo/bar" would match the rule "foo"."""
     return self._dir == other or other.startswith(self._dir + '/')
@@ skipping 18 matching lines @@
   """
   if not rule_string:
     raise Exception('The rule string "%s" is empty\nin %s' %
                     (rule_string, source))
 
   if not rule_string[0] in [Rule.ALLOW, Rule.DISALLOW, Rule.TEMP_ALLOW]:
     raise Exception(
       'The rule string "%s" does not begin with a "+", "-" or "!".' %
       rule_string)
 
-  return (rule_string[0], rule_string[1:])
+  return rule_string[0], rule_string[1:]
 
 
 class Rules(object):
   """Sets of rules for files in a directory.
 
   By default, rules are added to the set of rules applicable to all
   dependee files in the directory.  Rules may also be added that apply
   only to dependee files whose filename (last component of their path)
   matches a given regular expression; hence there is one additional
   set of rules per unique regular expression.
@@ skipping 46 matching lines @@
     Args:
       rule_string: The include_rule string read from the DEPS file to apply.
       source: A string representing the location of that string (filename, etc.)
               so that we can give meaningful errors.
       dependent_dir: The directory to which this rule applies.
       dependee_regexp: The rule will only be applied to dependee files
                        whose filename (last component of their path)
                        matches the expression. None to match all
                        dependee files.
     """
-    (rule_type, rule_dir) = ParseRuleString(rule_string, source)
+    rule_type, rule_dir = ParseRuleString(rule_string, source)
 
     if not dependee_regexp:
       rules_to_update = self._general_rules
     else:
       if dependee_regexp in self._specific_rules:
         rules_to_update = self._specific_rules[dependee_regexp]
       else:
         rules_to_update = []
 
     # Remove any existing rules or sub-rules that apply. For example, if we're
@@ skipping 14 matching lines @@
     dependee_filename = os.path.basename(dependee_path)
     for regexp, specific_rules in self._specific_rules.iteritems():
       if re.match(regexp, dependee_filename):
         for rule in specific_rules:
           if rule.ChildOrMatch(include_path):
             return rule
     for rule in self._general_rules:
       if rule.ChildOrMatch(include_path):
         return rule
     return MessageRule('no rule applying.')