Add compatibility with PyQt5 and python3.

PyQt5 is used by calibre since version 2.0.

Python3 is used by calibre since version 5.0.

theanarchistlibrary_store/theanarchistlibrary_plugin.py

@@ -2,13 +2,17 @@ __license__ = 'GPL 3'
 __copyright__ = '2012, Ruben Pollan <meskio@sindominio.net>'
 __docformat__ = 'restructuredtext en'
 
-import urllib2
-from contextlib import closing
+try:
+    from urllib.parse import quote
+except:
+    from urllib2 import quote
+try:
+    from PyQt5.Qt import QUrl
+except:
+    from PyQt4.Qt import QUrl
 
+from contextlib import closing
 import json
-
-from PyQt4.Qt import QUrl
-
 from calibre import browser
 from calibre.gui2 import open_url
 from calibre.gui2.store import StorePlugin
@@ -30,7 +34,7 @@ class TheAnarchistLibraryStore(BasicStoreConfig, StorePlugin):
             d.exec_()
 
     def search(self, query, max_results=10, timeout=60):
-        url = 'http://theanarchistlibrary.org/search?fmt=json&query=' + urllib2.quote(query)
+        url = 'http://theanarchistlibrary.org/search?fmt=json&query=' + quote(query)
 
         br = browser()