Change symbology of interpolation layer using ArcPy

Question

The code below creates many IDW rasters:

for date in all_dates:
    # Create a feature layer of each unique date
    where = "{0}=date '{1}'".format(arcpy.AddFieldDelimiters(datasource=fc, field=date_field),
                                    date.strftime('%Y-%m-%d'))
    arcpy.MakeFeatureLayer_management(in_features=fc, out_layer='lyr', where_clause=where)

    # For each field interpolate. This is untested since I dont have spatial analyst
    for fieldname in value_fields:
        outIDW = Idw(in_point_features='lyr', z_field=fieldname,
                     cell_size=10)  # , {power}, {search_radius}, {in_barrier_polyline_features})
        outIDW.save(os.path.join(output_folder, '{0}_{1}.tif'.format(fieldname, date.strftime('%Y%m%d'))))

as you know the generated rasters are in black and white(color ramp) I want to know if I can change them to other colors by using ArcPy not one by one in ArcMap.

Answer 1

The "Apply Symbology From Layer" tool does this. After the "outIDW.save" step, the layer will be the top-most layer in the map, so simply apply the symbology to the first layer in your map document. For example:

topLyr = arcpy.mapping.ListLayers(mxd, "*", df)[0]
symbologyLyr = r"C:\MyLayerFileFolder\someLayerFile.lyr"`
arcpy.management.ApplySymbologyFromLayer(topLyr, symbologyLyr)

(See Saving layers and layer packages).