Create polygons from csv file: RuntimeError: Object: CreateObject cannot create geometry from inputs

ZhexinYin

So I am kind of new to python world and I'm trying to create a polygon feature class including multiple polygons from a csv file attached (parcel_points.csv) containing 3 columns: "PARCELID", "POINT_X", "POINT_Y".

I followed the code sample from https://pro.arcgis.com/en/pro-app/latest/arcpy/get-started/writing-geometries.htm. I'm currently stuck on separating each polygon by "PARCELID" but I keep getting "RuntimeError: Object: CreateObject cannot create geometry from inputs". Where did I do wrong?

import os
import arcpy
import fileinput

in_dir = "D:/WPS/JHU/Programming in GIS AS.430.606.81.SP22/Week 13/Final"
csvFile = "parcel_points.csv"
fc = "polygonFromCSV"
geoType = "Polygon"
in_csv = os.path.join(in_dir, csvFile)
arcpy.env.workspace = in_dir

sr = arcpy.SpatialReference(26910)
arcpy.management.CreateFeatureclass(in_dir, fc, geoType, "", "", "", sr)

with arcpy.da.InsertCursor(fc, ["SHAPE@"]) as cursor:
	array = arcpy.Array()
	point = arcpy.Point()

	tempID = -1
	for line in fileinput.input(in_csv):
		if not fileinput.isfirstline():
			point.ID, point.X, point.Y = line.split(",")
			if tempID == -1:
				tempID = line[0]
			if tempID != line[0]:
				cursor.insertRow([arcpy.Polygon(array)])
				array.removeAll()
				point.removeAll()
			array.add(point)
			tempID = line[0]
	cursor.insertRow([arcpy.Polygon(array)])
	fileinput.close()

 

 

 

 

parcel_points.csv

MarkBryant

To fix your problem you will need to alter your code to:

• Add a field to the  output feature class to store the parcel id.
• Modify the insert cursor to also update this parcel update
• Insert the row with the geometry and the parcel id every time the parcel id changes.

The  code will look like this:

import csv
import os
import arcpy

in_dir = "D:/demo"
csvFile = "parcel_points.csv"
fc = "polygonFromCSV"
in_csv = os.path.join(in_dir, csvFile)
sr = arcpy.SpatialReference(26910)


# Create output feature class
arcpy.management.CreateFeatureclass(
    in_dir, fc, geometry_type="POLYGON", spatial_reference=sr
)
out_feature_class = os.path.join(in_dir, fc)
# Add a field to transfer PARCELID from input csv
arcpy.management.AddField(out_feature_class, "PARCELID", "LONG")

with arcpy.da.InsertCursor(out_feature_class, ["SHAPE@", "PARCELID"]) as cursor:
    point_list = []
    parcel_value = None
    is_first_pass = True

    with open(in_csv, mode="r") as csv_file:
        csv_reader = csv.reader(csv_file, delimiter=",")
        header = next(csv_reader)
        for row in csv_reader:
            #print(f"Parcel id:{row[0]} with X {row[1]} and Y {row[2]}.")

            if is_first_pass:
                parcel_value = row[0]
                is_first_pass = False
            elif row[0] != parcel_value:
                # Parcel ID has changed, write the polygon
                polygon = arcpy.Polygon(arcpy.Array(point_list), sr)
                cursor.insertRow([polygon, parcel_value])
                # Reset the current group
                parcel_value = row[0]
                point_list = []

            # Add the point to the feature's array of points
            point_list.append(arcpy.Point(row[1], row[2]))

        # final insert
        polygon = arcpy.Polygon(arcpy.Array(point_list), sr)
        cursor.insertRow([polygon, parcel_value])