Vjylku

I am new to scripting and to Python/arcpy. My intention with this script is to:

• select points from a featureclass that fall within a target polygon and that meet an attribute query specified by the 'amenities' variable.


• create three new featureclasses of these points.


• add a new textfield to each of the featureclasses.


• update that field.

I am stuck at the step where I would add the new field to each new feature class and update the cursor.

This is my first time posting on a message board, so I apologize if I have anything in the wrong format. Any advice would be helpful.

#Determine area of interst and make seperate shape files of amenities of interest

import arcpy

import os



arcpy.env.overwriteOutput = True



#Ammenities of interest

amenities = ['school', 'hospital', 'place of worship']

#Country of interest

targetCountry = 'El Salvador'

#Source of Data

dataSource = "Open Source"

#Central America shape file that is needed to find EL Salvador

countries = "C:\GEOG485\Lesson3\Lesson3Data\CentralAmerica.shp"

#All amenities are located here 

points = "C:\GEOG485\Lesson3\Lesson3Data\OSMpoints.shp"

#Output folder

targetPoints = "C:\GEOG485\Lesson3\Lesson3Data\Output"



arcpy.env.workspace = "C:\GEOG485\Lesson3"

#Isolate the country polygon of interest

try: 

    countryQuery = '"NAME" = ' + "'" + targetCountry + "'"

    print countryQuery



    arcpy.MakeFeatureLayer_management(countries, "targetCountryLayer", countryQuery)

    print arcpy.Exists("targetCountryLayer")



except:

    print ("Error, try again")



try:

    for amenity in amenities:

        amenitySelectionClause = '"amenity" = ' + "'" + amenity + "'"

        #Make a feature layer for the amenities of interest

        arcpy.MakeFeatureLayer_management(points, "pointLayer", amenitySelectionClause)

        #Narrow the amenities of interest to just inside the selected country

        arcpy.SelectLayerByLocation_management("pointLayer", "CONTAINED_BY", "targetCountryLayer")

        #Seperate shape file for each point of interest

        targetShp = os.path.join(targetPoints, "{}.shp".format(amenity))

        arcpy.CopyFeatures_management("pointLayer", targetShp)

        #Verify the field name that will be added to the attribute table and string size

        fieldName = arcpy.ValidateFieldName("Source")

        arcpy.AddField_management(targetShp, fieldName, "Text", "", "", 25)

        #Add row and enter text of where the data came from

        with arcpy.da.UpdateCursor(targetShp, fieldName) as cursor:

            for row in cursor:

                row = dataSource

                cursor.updateRow(row)

        print ("Sucess")



except:

    print ("Error, try again")



arcpy.Delete_management("targetCountryLayer")

arcpy.Delete_management("pointLayer")

print ("cleanup")