topic Re: Create polygons from csv file: RuntimeError: Object: CreateObject cannot create geometry from inputs in Python Questions

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

ZhexinYin — Mon, 02 May 2022 18:36:44 GMT

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()

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

DanPatterson — Sat, 30 Apr 2022 03:13:38 GMT

import numpy as np import arcpy name = "c:/temp/parcel_points.csv" dt = np.dtype([('PARCELID', 'i8'), ('POINT_X', 'f8'), ('POINT_Y', 'f8')]) a = np.genfromtxt( name, dtype=dt, delimiter=",", names=True, autostrip=True, encoding=None) ids = a['PARCELID'] w = np.nonzero((ids[1:] - ids[:-1] != 0))[0] p_lst = np.array_split(a, w) frst = p_lst[0] xs = frst[['POINT_X', 'POINT_Y']].tolist() p = arcpy.Polygon(arcpy.Array([arcpy.Point(i[0], i[1]) for i in xs]))

'p' is the first polygon (line 11 and 12) in the 'p_list' which was obtained from splitting the array based on where the PARCELID s breakpoints occurred.

You can cobble the rest of the polygons by creating a list to hold the polygons and cycle through lines 11 to 13.

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

ZhexinYin — Sun, 01 May 2022 20:18:58 GMT

Thank you so much for the help! I forgot to mention that the task has to be completed via insertcursor method. I believe I'm almost there since I was able to create an unseparated polygon through the code below. I'm just not able to separate them through ID.

import os import arcpy import fileinput in_dir = "D:/demo" 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() for line in fileinput.input(in_csv): if not fileinput.isfirstline(): point.ID, point.X, point.Y = line.split(",") array.add(point) cursor.insertRow([arcpy.Polygon(array)]) fileinput.close()

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

DanPatterson — Mon, 02 May 2022 00:34:03 GMT

Has to be done by an insertcursor?

cobble the parts from above that does the splitting, then throw it into your cursor if you must

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

ZhexinYin — Mon, 02 May 2022 18:40:41 GMT

I have updated the code above and solved the runtime error. It was caused by false indentation. But the code still not able to separate polygons by ID. Is there anyway this code can be improved instead of rewriting the whole thing to make it work?

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

MarkBryant — Wed, 04 May 2022 10:27:47 GMT

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])

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

ZhexinYin — Wed, 11 May 2022 20:47:17 GMT

Thank you!