Setting symbology of a layer using arcpy.mapping?

Question

In the help docs they mention the ability to update layer symbology. (http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Geoprocessing_scripts_for_map_document_management_and_output/00sr00000009000000/)

I haven't been able to find the function, class or module that does this. Can anyone point me in the right direction? Or does anyone have any examples to share?

thanks

JoshuaChan · Answer

Does anyone know how to set a layer's label to be turned on using arcpy.mapping? 
and also to set the label field, the format (eg. round([field1],2) & " m")  and also the font and font size?

sorry I don't quite understand.
In my script I'm creating a temporary data layer, and adding it to my mxd. I then want to make the symbol invisible but turn the labels on. So I need to set the label item, the font, the font size, and the color of the lines to be clear. Does Update Layer do that?  The examples seem to be copying over the layer symbology from another existing layer in the mxd. So should I create a dummy layer that has the symbology that just sits in my mxd for the purposes of copying over the symbology definitions?

JoshuaChan · Answer

UpdateLayer.

sorry I don't quite understand.
In my script I'm creating a temporary data layer, and adding it to my mxd. I then want to make the symbol invisible but turn the labels on. So I need to set the label item, the font, the font size, and the color of the lines to be clear. Does Update Layer do that?  The examples seem to be copying over the layer symbology from another existing layer in the mxd. So should I create a dummy layer that has the symbology that just sits in my mxd for the purposes of copying over the symbology definitions?

JasonScheirer · Answer

UpdateLayer.