support extend-exclude Fixes #535

src/flake8/checker.py

@@ -1,6 +1,7 @@
 """Checker Manager and Checker classes."""
 import collections
 import errno
+import itertools
 import logging
 import signal
 import tokenize
@@ -79,6 +80,9 @@ class Manager(object):
             "physical lines": 0,
             "tokens": 0,
         }
+        self.exclude = tuple(
+            itertools.chain(self.options.exclude, self.options.extend_exclude),
+        )
 
     def _process_statistics(self):
         for checker in self.checkers:
@@ -187,7 +191,7 @@ class Manager(object):
 
         return utils.matches_filename(
             path,
-            patterns=self.options.exclude,
+            patterns=self.exclude,
             log_message='"%(path)s" has %(whether)sbeen excluded',
             logger=LOG,
         )

src/flake8/main/options.py

@@ -14,6 +14,7 @@ def register_default_options(option_manager):
     - ``--count``
     - ``--diff``
     - ``--exclude``
+    - ``--extend-exclude``
     - ``--filename``
     - ``--format``
     - ``--hang-closing``
@@ -85,6 +86,16 @@ def register_default_options(option_manager):
         " (Default: %default)",
     )
 
+    add_option(
+        "--extend-exclude",
+        metavar="patterns",
+        default="",
+        parse_from_config=True,
+        comma_separated_list=True,
+        help="Comma-separated list of files or directories to add to the list"
+        " of excluded ones."
+    )
+
     add_option(
         "--filename",
         metavar="patterns",