[GRASS-dev] grass standalone

how to run a custom grass viewer outside grass shell
eg
python render.py

but it gives me error

Initializing…
Traceback (most recent call last):
File “grass-qt/render.py”, line 1308, in
image = map.Render(force = True)
File “grass-qt/render.py”, line 865, in Render
os.environ[“GRASS_REGION”] = self.SetRegion(windres)
File “grass-qt/render.py”, line 697, in SetRegion
region = self.AdjustRegion()
File “grass-qt/render.py”, line 484, in AdjustRegion
mapwidth = abs(self.region[“e”] - self.region[“w”])
KeyError: ‘e’
Exception AttributeError: “‘NoneType’ object has no attribute ‘GetCmdString’” in <bound method MapLayer.del of <main.MapLayer object at 0xa40f08c>> ignored
Exception AttributeError: “‘NoneType’ object has no attribute ‘GetCmdString’” in <bound method MapLayer.del of <main.MapLayer object at 0xa3ebfec>> ignored

Thanks && Regards
Rashad