Convert code to Python 3-compatible

addon.xml

@@ -5,6 +5,7 @@ name="Example Kodi Video Plugin"
 provider-name="Roman_V_M">
 <requires>
   <import addon="xbmc.python" version="2.25.0"/>
+  <import addon="script.module.future" />
 </requires>
 <extension point="xbmc.python.pluginsource" library="main.py">
   <provides>video</provides>

main.py

@@ -3,10 +3,23 @@
 # Author: Roman V. M.
 # Created on: 28.11.2014
 # License: GPL v.3 https://www.gnu.org/copyleft/gpl.html
+"""
+Example video plugin that is compatible with both Python 2 and 3
 
+Compatibility features are provided by ``script.module.future`` library addon.
+"""
+
+# Enable unicode strings by default as in Python 3
+from __future__ import unicode_literals
+# Monkey-patch standard libary names to enable Python 3-like behavior
+from future import standard_library
+standard_library.install_aliases()
+# The above strings provide compatibility layer for Python 2
+# so the code can work in both versions.
+# In Python 3 they do nothing and can be safely removed.
+# Normal imports for your addon:
 import sys
-from urllib import urlencode
-from urlparse import parse_qsl
+from urllib.parse import urlencode, parse_qsl
 import xbmcgui
 import xbmcplugin
 
@@ -65,7 +78,6 @@ def get_url(**kwargs):
     Create a URL for calling the plugin recursively from the given set of keyword arguments.
 
     :param kwargs: "argument=value" pairs
-    :type kwargs: dict
     :return: plugin call URL
     :rtype: str
     """
@@ -86,7 +98,7 @@ def get_categories():
     :return: The list of video categories
     :rtype: types.GeneratorType
     """
-    return VIDEOS.iterkeys()
+    return VIDEOS.keys()
 
 
 def get_videos(category):