Select Layer by Location using ArcPy?

Question

i want to create a python scipt query using arpy in arcgis i have one polyline shapefile and one polygon shapefile i want to choose(select) the polygons where contained within in the polylines shapefiles or there intersections and finaly i want that select polygons to export to new shapefile layer. i use arcmap 10.1

my code is

# Import arcpy module
import arcpy
from arcpy.sa import *
arcpy.CheckOutExtension("spatial")
arcpy.env.overwriteOutput = True
try:
arcpy.env.workspace = root
root = arcpy.GetParameterAsText(0)
polygon = arcpy.GetParameterAsText(1)
line = arcpy.GetParameterAsText(2)
except:
arcpy.AddMessage(arcpy.GetMessages())
try:
arcpy.SelectLayerByLocation_management(polygon, "INTERSECT", line, "", "NEW_SELECTION")
arcpy.FeatureClassToShapefile_conversion("polygon", newpolygon)
newpolygon = root + "\\newpolygon"
except:
arcpy.AddMessage(arcpy.GetMessages())

i use that code but i dont take Correct Results my root workspace is empty

any idea ?

• phloem: You attempt to use the variable "newpolygon" before it is assigned a value.
• phloem: Similarly, as Leroy points out below, you attempt to use "root" before it is assigned.

Answer 1

This script can be further edited but commonly this script should work

import arcpy
# Script arguments
Search_Distance = arcpy.GetParameterAsText(0)
Selection_type = arcpy.GetParameterAsText(1)
if Selection_type == '#' or not Selection_type:
 Selection_type = "NEW_SELECTION" # provide a default value if unspecified
Source_Layer = arcpy.GetParameterAsText(2)
Relationship = arcpy.GetParameterAsText(3)
if Relationship == '#' or not Relationship:
 Relationship = "INTERSECT" # provide a default value if unspecified
Target_Layers__Select_From_ = arcpy.GetParameterAsText(4)
Output_Layer_Name = arcpy.GetParameterAsText(5)
Output_Layer = arcpy.GetParameterAsText(6)
Workspace_or_Feature_Dataset = arcpy.GetParameterAsText(7)
# Local variables:
# Process: Select Layer By Location
arcpy.SelectLayerByLocation_management(Target_Layers__Select_From_, Relationship, Source_Layer, Search_Distance, Selection_type)
# Process: Make Feature Layer
arcpy.MakeFeatureLayer_management(Output_Layer_Name, Output_Layer, "", Workspace_or_Feature_Dataset, "")

Thanks.

Answer 2

import arcpy
polygon = arcpy.GetParameterAsText(0) # input polygon feature class
line = arcpy.GetParameterAsText(1) # input line feature class
output = arcpy.GetParameterAsText(2) # output polygon feature class
# make polygon feature layer
arcpy.MakeFeatureLayer_management(polygon, 'polygon_lyr') 
# select polygons
arcpy.SelectLayerByLocation_management('polygon_lyr', "INTERSECT", line, "", "NEW_SELECTION")
# save selection to output
arcpy.CopyFeatures_management('polygon_lyr', output)

Answer 3

You need to place 'root = arcpy.GetParameterAsText(0)' before 'arcpy.env.workspace = root' and that should sort it. Watch your script indentation too :)