Port redshift-gtk to Python3

Python 2 is no longer supported

configure.ac

@@ -27,7 +27,7 @@ PKG_CHECK_MODULES([GEOCLUE], [geoclue], [have_geoclue=yes], [have_geoclue=no])
 AC_CHECK_HEADER([windows.h], [have_windows_h=yes], [have_windows_h=no])
 
 # Check for Python
-AM_PATH_PYTHON([2.6], [have_python=yes], [have_python=no])
+AM_PATH_PYTHON([3.3], [have_python=yes], [have_python=no])
 
 # Check RANDR method
 AC_MSG_CHECKING([whether to enable RANDR method])

src/redshift-gtk/Makefile.am

@@ -11,11 +11,14 @@ redshift_gtkdir = $(pythondir)/redshift_gtk
 dist_bin_SCRIPTS = redshift-gtk
 endif
 
-EXTRA_DIST = defs.py.in
-CLEANFILES = defs.py
+EXTRA_DIST = defs.py.in redshift-gtk.in
+CLEANFILES = defs.py redshift-gtk
 
 
 # Local python definitions
 defs.py: defs.py.in
 	$(AM_V_GEN)sed -e "s|\@bindir\@|$(bindir)|g" \
 		-e "s|\@localedir\@|$(localedir)|g" $< > $@
+
+redshift-gtk: redshift-gtk.in
+	$(AM_V_GEN)sed -e "s|\@pythondir\@|$(pythondir)|g" $< > $@

src/redshift-gtk/redshift-gtk.in

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # redshift-gtk -- GTK+ Redshift launcher script
 # This file is part of Redshift.
 
@@ -17,6 +17,10 @@
 
 # Copyright (c) 2010  Jon Lund Steffensen <jonlst@gmail.com>
 
+import sys
+
+# Some non-standard install paths may need to be added
+sys.path.append('@pythondir@')
 
 if __name__ == '__main__':
     from redshift_gtk.statusicon import run

src/redshift-gtk/statusicon.py

@@ -34,8 +34,8 @@ try:
 except ImportError:
     appindicator = None
 
-import defs
-import utils
+from . import defs
+from . import utils
 
 _ = gettext.gettext
 
@@ -99,7 +99,7 @@ class RedshiftStatusIcon(object):
         try:
             autostart_item.set_active(utils.get_autostart())
         except IOError as strerror:
-            print strerror
+            print(strerror)
             autostart_item.set_property('sensitive', False)
         else:
             autostart_item.connect('toggled', self.autostart_cb)
@@ -185,7 +185,7 @@ class RedshiftStatusIcon(object):
         # Start child process with C locale so we can parse the output
         env = os.environ.copy()
         env['LANG'] = env['LANGUAGE'] = env['LC_ALL'] = env['LC_MESSAGES'] = 'C'
-        self.process = GLib.spawn_async(args, envp=['{}={}'.format(k,v) for k, v in env.iteritems()],
+        self.process = GLib.spawn_async(args, envp=['{}={}'.format(k,v) for k, v in env.items()],
                                         flags=GLib.SPAWN_DO_NOT_REAP_CHILD,
                                         standard_output=True, standard_error=True)
 
@@ -299,7 +299,7 @@ class RedshiftStatusIcon(object):
 
     def child_data_cb(self, f, cond, data):
         stdout, ib = data
-        ib.buf += os.read(f, 256)
+        ib.buf += os.read(f, 256).decode('utf-8')
 
         # Split input at line break
         sep = True