[booru] rewrite using Mixin classes (#59)

- improved code structure
- improved URL patterns
- better pagination to work around page limits on
  - Danbooru
  - e621
  - 3dbooru

gallery_dl/extractor/safebooru.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2017 Mike Fährmann
+# Copyright 2015-2018 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -11,31 +11,32 @@
 from . import booru
 
 
-class SafebooruExtractor(booru.XMLBooruExtractor):
+class SafebooruExtractor(booru.XmlParserMixin,
+                         booru.GelbooruPageMixin,
+                         booru.BooruExtractor):
     """Base class for safebooru extractors"""
     category = "safebooru"
     api_url = "https://safebooru.org/index.php"
-    pagestart = 0
-    pagekey = "pid"
 
-    def setup(self):
+    def __init__(self, match):
+        super().__init__(match)
         self.params.update({"page": "dapi", "s": "post", "q": "index"})
 
 
-class SafebooruTagExtractor(SafebooruExtractor, booru.BooruTagExtractor):
+class SafebooruTagExtractor(booru.TagMixin, SafebooruExtractor):
     """Extractor for images from safebooru.org based on search-tags"""
     pattern = [(r"(?:https?://)?(?:www\.)?safebooru\.org/(?:index\.php)?"
-                r"\?page=post&s=list&tags=([^&]+)")]
+                r"\?page=post&s=list&tags=(?P<tags>[^&#]+)")]
     test = [("http://safebooru.org/index.php?page=post&s=list&tags=bonocho", {
         "url": "17c61b386530cf4c30842c9f580d15ef1cd09586",
         "content": "e5ad4c5bf241b1def154958535bef6c2f6b733eb",
     })]
 
 
-class SafebooruPostExtractor(SafebooruExtractor, booru.BooruPostExtractor):
+class SafebooruPostExtractor(booru.PostMixin, SafebooruExtractor):
     """Extractor for single images from safebooru.org"""
     pattern = [(r"(?:https?://)?(?:www\.)?safebooru\.org/(?:index\.php)?"
-                r"\?page=post&s=view&id=(\d+)")]
+                r"\?page=post&s=view&id=(?P<post>\d+)")]
     test = [("http://safebooru.org/index.php?page=post&s=view&id=1169132", {
         "url": "cf05e37a3c62b2d55788e2080b8eabedb00f999b",
         "content": "93b293b27dabd198afafabbaf87c49863ac82f27",