def _set_zeroes_invisible(self, layer):
self.out("setting zeroes to 100% transparency")
"""
# Set 0 values to NODATA (= transparent):
provider = active_raster_layer.dataProvider()
provider.setNoDataValue(1, 0) # first one is referred to band number
# -> is working
"""
# better, conserves 0 value:
tr = QgsRasterTransparency()
tr.initializeTransparentPixelList(0)
layer.renderer().setRasterTransparency(tr)
