topic Re: Python - Create duplicate polygons based on number of intersects with points fc in Geoprocessing Questions

Python - Create duplicate polygons based on number of intersects with points fc

KevinCressy — Mon, 02 Aug 2010 15:05:20 GMT

Hello all,

Does anyone know

I have been trying to write a script that will create duplicate polygons based on the number of points that intersect each polygon.

The catch is that I want the output polygon feature class to include the "name" of the point layer intersecting it.

So if I have three points: ID1, ID1 and ID3 intersecting polygon A I would like a polygon feature class with an attribute table showing:

FID, PolygonName, PointName
0, A, ID1
1, A, ID2
2, A, ID3
3, B, etc, etc, etc

Is this possible in python? I have been struggling with getting this to work with the following code....

Any help would be appreciated!

Regards,

Kevin

import arcgisscripting
gp = arcgisscripting.create(9.3)
print "Step1"
# Load required toolboxes...
gp.AddToolbox(r"C:\Program Files\ArcGIS\ArcToolbox\Toolboxes\Data Management Tools.tbx")

Output_Layer_Name = "Polygons_Layer"
Polygons_shp = r"C:\Temp\ES106506\Polygons.shp"
Polygons_Layer = "Polygons_Layer"
Output_Feature_Class = "C:\\Temp\\ES106506\\Polygons_CopyFeatures.shp"

gp.Workspace = r"C:\Temp\ES106506\output.gdb"
gp.OverWriteOutput = 1
try:
#Define the points layer
gp.MakeFeatureLayer(r"C:\Temp\ES106506\Points.shp", "Points_Layer")
#Define the polygons layer
gp.MakeFeatureLayer(Polygons_shp, Polygons_Layer)
print "Step5"
#create search cursor to loop through points
points = gp.searchCursor("Points_Layer")
print "Step6"
#For each point select the polygon intersecting it

point = points.next()
while points:
gp.selectLayerByLocation(Polygons_Layer, "INTERSECT", point.shape)
#Create a new Polygon feature class based on the original Point
#feature class and named based on a field within the the polygon field
name = Polygons_Layer.TempID
gp.CopyFeatures(Polygons_Layer, Polygons_Layer.name)

#move on to next point
point = points.next()
print "Finished"
del gp, points, point

except:
print gp.getmessages()
print "Errored"
del gp

Re: Python - Create duplicate polygons based on number of intersects with points fc

ChrisSnyder — Mon, 02 Aug 2010 17:17:49 GMT

Check out the SpatialJoin tool. This should do exatly what you want.

Make the TargetFeatures your polygons, the JoinFeatures your points. Be sure to specify the join operation as a 'JOIN_ONE_TO_MANY'.

Re: Python - Create duplicate polygons based on number of intersects with points fc

KevinCressy — Thu, 05 Aug 2010 18:50:24 GMT

Thanks for that - that does solve the problem - however I am still keen to crack with python.

Les Smith from ESRI UK kindly pointed out an error in my code i.e.

"I think this bit of code:

point = points.next()
while points:

should be

point = points.next()
while point:"

I have modified the code below but I still seem to be having an issue.

The code seems to be working up to the first selection - however then I want to take this selected feature and add the value of the field from the point layer to this polygon feature class. perhaps I need to do a join on this selected feature and the point in the feature class????

import arcgisscripting
gp = arcgisscripting.create(9.3)

# Load required toolboxes...
gp.AddToolbox(r"C:\Program Files\ArcGIS\ArcToolbox\Toolboxes\Data Management Tools.tbx")

Output_Layer_Name = "Polygons_Layer"
Polygons_shp = r"C:\Temp\ES106506\Polygons.shp"
Polygons_Layer = "Polygons_Layer"
Output_Feature_Class = r"C:\Temp\ES106506\Polygons_CopyFeatures.shp"

gp.Workspace = r"C:\Temp\ES106506\output.gdb"
gp.OverWriteOutput = 1

try:
#Define the points layer
gp.MakeFeatureLayer(r"C:\Temp\ES106506\Points.shp", "Points_Layer")

#Define the polygons layer
gp.MakeFeatureLayer(Polygons_shp, Polygons_Layer)

#create search cursor to loop through points
points = gp.searchCursor("Points_Layer")

#For each point select the polygon intersecting it

point = points.next()
while point:
gp.selectLayerByLocation(Polygons_Layer, "INTERSECT", point.shape)

#Create a new Polygon feature class based on the original Point
#feature class and named based on a field within the the polygon field
name = Polygons_Layer.TempID
gp.CopyFeatures(Polygons_Layer, Polygons_Layer.name)

#move on to next point
point = points.next()
print "Finished"
del gp, points, point

except:
print gp.getmessages()
print "Errored"
del gp