Update Z values of polygon veritices with multiparts and donuts [duplicate]

Question

I am trying to update Z values of the vertices of the polygon shape. The script bellow works for polygons without multiparts and donuts. If I run this script for polygon shape that contains multiparts and donuts, I get error. How can I make it work?

My script:

import arcpy

fc = r"C:\Scratch\fcTest.shp"

# Get Spatial Reference of dataset
desc = arcpy.Describe(fc)
sr = desc.spatialReference

with arcpy.da.UpdateCursor(fc, ["SHAPE@"]) as cursor:
    for row in cursor:

        # Get Geometry
        geom = row[0]

        # Create an empty array object
        arr = arcpy.Array()

        # Read points, if Z is found to be zero reset it to 1
        for part in geom:
            for pnt in part:
                if not pnt:
                    arr.add(None)
                    continue

                if pnt.Z == 0:
                    pnt.Z = 1.0

                 # Add updated point to Array
                arr.add(pnt)

        # Construct new polygon geometry from array whilst setting spatial reference and indicating it has Z
        newpoly = arcpy.Polygon(arr,sr,True)

        #Update row
        cursor.updateRow([newpoly])

Error:

 Traceback (most recent call last):
 File "C:\Scratch\fcTest.py", line 21, in <module>
    if pnt.Z == 0:
  AttributeError: 'NoneType' object has no attribute 'Z'
   >>> 

Answer 1

I suggest you to give the explode_to_points if the UpdateCursror a try in this case.

If you set it to True, each row of your cursor will be each vertex of your polygons.

I did not tested it, but you can try something like the below:

import arcpy

fc = r"C:\Scratch\fcTest.shp"

# Get Spatial Reference of dataset
desc = arcpy.Describe(fc)
sr = desc.spatialReference

with arcpy.da.UpdateCursor(fc, ["SHAPE@Z"], explode_to_points=True) as cursor:
    for row in cursor:
        if row[0] == 0:
            row[0] = 1.0
        cursor.updateRow(row)