643def fetch_band_nodata(band, default = 0):
644 assert band is not None
645
646 nodata = default
647 if band.GetNoDataValue() is not None:
648 nodata = band.GetNoDataValue()
649 else:
650 logit("WARNING: No nodata flagged in raster_columns metadata. "
651 "In serialized raster, nodata bytes will have value of 0.\n")
652 return nodata
653