Select by polygon - python

Question

I need to create a python script where the user can ???select by polygon??? and the selection is then created into a new feature class.  Do I need to use ArcObjects for this? I am currently using ArcGIS 10 and python, but don???t have much experience with ArcObjects. Doing this with a model is easy, but the user would like it to be automated.

Thanks

kv

kristinavucic · Answer

Thank you very much for your replies. I have used Feature Set as my input and it works perfectly.

MikeMacRae · Answer

You need to use some geoprocessing tools. Try the "SelectByAttribute" tool to select your polygon from the attribute table. You need to convert the attribute table to a feature layer to in order to make it selectable. Here's a peice from a script of mine that might help. It helps you select points in polygons, but the general idea of what you are looking to do is there:# Converts unselectable feature class into a selectable feature layer
gp.MakeFeatureLayer(POINT,"point")
gp.MakeFeatureLayer(POLYGON,"polygon")

rows = gp.SearchCursor("polygon")
row = rows.Next()

gp.AddMessage("Calculating Points in Polgons...")

try:

while row:
       
        #gp.AddMessage(row.OBJECTID)

# Select each record inside of the polygon feature class    
        SelPoly = gp.SelectLayerByAttribute("polygon", "NEW_SELECTION", "\"OBJECTID\" =" + str(row.OBJECTID))
        #gp.AddMessage(row.OBJECTID)
            
        # Select all the point that are inside of the polygon record
        SelPts = gp.SelectLayerByLocation("point", "WITHIN", SelPoly, 0, "NEW_SELECTION")
        
        # Count the points that are in each polygon
        GetCount = gp.GetCount_management(SelPts)
        
        # Calculate the ASSOC_PTS field with the counted points
        gp.CalculateField_management("polygon", "ASSOC_PTS", GetCount, "VB", "")

# Move to the next row   
        row = rows.Next()

KimOllivier · Answer

There is a datatype in the tool properties that allows you to sketch a polygon (or point or line) graphic that is passed into the script. You can create a featureclass from it. The data type is a featureset. You need a template defined in a layer file to use it.

You can sketch any type of polygon as in the draw tool, edit it and add attributes to fields defined in the template.