Index: abp/filters/__init__.py
===================================================================
--- a/abp/filters/__init__.py
+++ b/abp/filters/__init__.py
@@ -8,12 +8,121 @@
 # Adblock Plus is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
 
-# flake8: noqa
-from .parser import *
-from .renderer import *
-from .sources import *
+"""Tools for working with Adblock Plus filter lists.
+
+This is a library for parsing and rendering filter lists that are used by
+adblocking software to determine what content to block and what to let through.
+
+Example
+-------
+
+    from abp.filters import parse_filterlist
+
+    with open(fl_path, 'rt') as fl_file:
+        for line in parse_filterlist(fl_file):
+            if line.type == 'filter':
+                print('Filter:' + line.text)
+                print('| Selector: {0[type]}:{0[value]}'.format(line.selector))
+                print('| Action: ' + line.action)
+                for key, value in line.options:
+                    print('| Option[{}]: {}'.format(key, value))
+
+Exported members
+----------------
+
+Functions:
+
+  - parse_filterlist - Parse a filter list from an iterable of strings.
+  - parse_line - Parse one line of a filter list.
+  - render_filterlist - Combine filter list fragments into a filter list.
+
+Filter list fragment sources for filter list rendering:
+
+  - WebSource - loads fragments from the web.
+  - FSSource - loads fragments from a directory on the filesystem.
+  - TopSource - a specialized FSSource that represents current directory and
+    should be used as the starting source of render_filterlist.
+
+Exceptions that thrown by the functions in this module:
+
+  - ParseError - thrown by the parser when invalid input is encountered.
+  - IncludeError - thrown by the renderer when an include instruction cannot
+    be processed.
+  - MissingHeader - thrown by the renderer when the output doesn't start with a
+    header.
+
+Constants for code that works with filter lists:
+
+  - SELECTOR_TYPE - Namespace for constants that determine how the filter
+    matches content (for example: SELECTOR_TYPE.CSS):
+
+    - URL_PATTERN - Match URL against a pattern (see
+      https://adblockplus.org/filters#basic),
+    - URL_REGEXP - Match URL against a regular expression,
+    - CSS - Select elements via a CSS selector,
+    - XCSS - CSS selector with extensions (to emulate CSS4),
+    - ABP_SIMPLE - Deprecated simplified element selection syntax.
+
+  - FILTER_ACTION - Namespace for constants that determine what the filter does
+    with selected content (for example: FILTER_ACTION.BLOCK):
+
+    - BLOCK - Block the request,
+    - ALLOW - Allow the request (even if blocked by other filters),
+    - HIDE - Hide selected element,
+    - SHOW - Show selected element (even if hidden by other filters).
+
+  - FILTER_OPTION - Namespace for filter option constants (for example
+    FILTER_OPTION.IMAGE). See https://adblockplus.org/filters#options for the
+    full list of options.
+
+See docstrings of module members for further information.
+
+Notes
+-----
+`str` in function and method signatures always means a unicode string (Python3
+meaning of `str`).
+
+"""
+
+from .parser import (
+    FILTER_ACTION,
+    FILTER_OPTION,
+    SELECTOR_TYPE,
+    ParseError,
+    parse_filterlist,
+    parse_line,
+)
+from .renderer import (
+    IncludeError,
+    MissingHeader,
+    render_filterlist,
+)
+from .sources import (
+    FSSource,
+    TopSource,
+    WebSource,
+)
+
+__all__ = [
+    # Constants
+    'FILTER_ACTION',
+    'FILTER_OPTION',
+    'SELECTOR_TYPE',
+    # Exceptions
+    'ParseError',
+    'IncludeError',
+    'MissingHeader',
+    # File sources
+    'FSSource',
+    'TopSource',
+    'WebSource',
+    # Functions
+    'parse_filterlist',
+    'parse_line',
+    'render_filterlist',
+]