fix python 2/3 compatibility for xrange->range

pysstv/color.py

@@ -1,7 +1,12 @@
 #!/usr/bin/env python
 
 from __future__ import division
-from builtins import range  # python 2/3 compatibility
+try:  # python 2/3 compatibility
+    xrange  # will fail in python 3
+except NameError:
+    pass
+else:
+    range = xrange
 from pysstv.sstv import byte_to_freq, FREQ_BLACK, FREQ_WHITE, FREQ_VIS_START
 from pysstv.grayscale import GrayscaleSSTV
 from itertools import chain

pysstv/grayscale.py

@@ -1,7 +1,13 @@
 #!/usr/bin/env python
 
 from __future__ import division
-from builtins import range  # python 2/3 compatibility
+
+try:  # python 2/3 compatibility
+    xrange  # will fail in python 3
+except NameError:
+    pass
+else:
+    range = xrange
 from pysstv.sstv import SSTV, byte_to_freq
 
 

pysstv/sstv.py

@@ -12,8 +12,13 @@ try:
     import itertools.izip as zip  # python 2
 except ImportError:
     pass  # python 3
-from builtins import range  # python 2/3 compatibility
 from itertools import cycle, chain
+try:  # python 2/3 compatibility
+    xrange  # will fail in python 3
+except NameError:
+    pass
+else:
+    range = xrange
 from array import array
 import wave