Select by Location using first points of polyline

Question

I am trying to select a point from a point layer that intersect a polyline layers firstpoint and using arcpy. I am getting an error "ExecuteError: ERROR 000622: Failed to execute (Select Layer By Location). Parameters are not valid. ERROR 000623: Invalid value type for parameter select_features."

import arcpy
def main():
 arcpy.env.workspace = r'D:\My Documents\SR91_FeasibilityStudy\GISData\SR-91.gdb'
 arcpy.MakeFeatureLayer_management('Build2035', 'plLayer') #polyline Layer
 arcpy.MakeFeatureLayer_management('Build2035_pts_CollectEvents', 'ptLayer') #point Layer
 with arcpy.da.SearchCursor('plLayer',("Shape@","OID@")) as cursor:
 for row in cursor:
 arcpy.SelectLayerByLocation_management('ptLayer','intersect',row[0].firstPoint)
 result = arcpy.GetCount_management('ptLayer')
 print result

• klewis: You can save the first point of each Polyline using "Feature Vertices To Points", enter START as the 3rd parameter. Then intersect the two Point layers.

Answer 1

If you want to perform a selection for each row, as your script indicates, you need to convert your point object to a geometry object. Here's a very messy line of code that will do so:

arcpy.SelectLayerByLocation_management('ptLayer','intersect',arcpy.Geometry ("point", row[0].firstPoint, arcpy.Describe ('Build2035').spatialReference))

If you want to perform a single selection based off of all first points, create a new feature class and export your first points to it using a cursor (or if you have an advanced license, use Feature Vertices To Points as described by klewis in the comments).

Something like this (untested):

import arcpy
def main():
 arcpy.env.workspace = r'D:\My Documents\SR91_FeasibilityStudy\GISData\SR-91.gdb'
 arcpy.MakeFeatureLayer_management('Build2035_pts_CollectEvents', 'ptLayer') #point Layer
 #Create empty point feature class for first points
 outPath = arcpy.env.workspace
 arcpy.CreateFeatureclass_management (outPath, "FirstPoints", "POINT", spatial_reference = 'Build2035')
 #add firstpoints to feature class
 with arcpy.da.SearchCursor ('Build2035', "SHAPE@") as sCurs:
 with arcpy.da.InsertCursor ("FirstPoints", "SHAPE@") as iCurs:
 for geom, in sCurs:
 row = (geom.firstPoint,)
 iCurs.insertRow (row)
 #select points by first points feature class
 arcpy.SelectLayerByLocation_management('ptLayer','intersect', "FirstPoints")
 result = arcpy.GetCount_management('ptLayer').getOutput (0)
 print result