Changing legend item properties using ArcPy

Question

I'm developing a Python script to created several map document (.mxd) files from .shp file and .xlsx file automatically. After setting symbology of layer and changing labels, I want to hide heading of legend by working on "show heading" option on "Legend Item Properties", but unfortunately I cannot found this property. Here is part of my code:

def CreateMXD(srcMXDDir, srcMXDName, srcSHPDir, srcLyrDir, srcStyleName, srcXlsxWB):
 srcLayer = arcpy.mapping.Layer(srcLyrDir)
 mxd = arcpy.mapping.MapDocument(srcMXDDir + "//" + srcMXDName + '.mxd')
 mxdDF0 = arcpy.mapping.ListDataFrames(mxd, "Layers")[0]
 # mxdDF1 = arcpy.mapping.ListDataFrames(mxd2, "Layers")[1]
 mxdLayer = arcpy.mapping.Layer(srcSHPDir)
 arcpy.mapping.AddLayer(mxdDF0, mxdLayer, "TOP")
 addLayer = arcpy.mapping.ListLayers(mxd, "", mxdDF0)[0]
 fields = arcpy.ListFields(srcSHPDir)
 for field in fields:
 fieldType = field.type
 fieldName = field.name
 if fieldType in ["Double", "Integer", "Long"] and fieldName.startswith('edu'):
 arcpy.mapping.UpdateLayer(mxdDF0, addLayer, srcLayer, True)
 # print(addLayer.symbologyType)
 if addLayer.symbologyType == 'GRADUATED_COLORS':
 addLayer.symbology.valueField = fieldName
 labels = addLayer.symbology.classBreakLabels
 try:
 addLayer.symbology.classBreakLabels = ["{} - {}".format(*r)
 for r in [
 [round(float(f), 2) for f in lab.split(" - ")]
 for lab in labels
 ]
 ]
 except:
 print('Error in Symbology | %s' % fieldName)

This link has described this functionality in ArcMap but I want to do this change using ArcPy scripting. Below you can see the screen of my MXD file and mentioned option in ArcMap:

Arcmap show heading option

Answer 1

Using ArcGIS 10.4 (not Pro version), I did this by defining new style and then updating legend. So by double-click on labels in legend an going to Legend Properties > Style... > Properties... I could turn Show Heading option off. After applying changes, I named it df0_legend_style and saved it as a new style. Below image shows how we can create new style in ArcMap:

enter image description here

When I created the style, I added these codes to my script:

newStyle = arcpy.mapping.ListStyleItems("USER_STYLE", "Legend Items", df0_legend_style)[0]
mxd_legend = arcpy.mapping.ListLayoutElements(mxd, "LEGEND_ELEMENT")[0]
mxd_legend.title = ""
mxd_legend.updateItem(addLayer, newStyle)
mxd.saveACopy('newMXD.mxd')

This code update Legend Item by newly created style.

Answer 2

As commented by @Vince:

ArcPy does not support all ArcObjects functionality, especially with regard to mapping and symbology.

In ArcGIS Pro there is an ItemGroup class and:

The ItemGroup class allows you to change a heading value for a group and more importantly provides access to the individual items in each group.

However, the ItemGroup class appears to only be available for a UniqueValuesRenderer.

Since you are using ArcMap and a GraduatedColorsRenderer, the above will not provide a solution but it may provide some ideas about where to look for the functionality you seek within ArcGIS Desktop when you are using ArcPy with ArcGIS Pro.