Proper syntax for Select Feature Layer by Location

Question

Can someone let me know how I can use a single feature from one layer as the "Select Features" when using the Make Feature Layer by Location tool with another layer as the input?

In the code below I have no idea what to put in place of BLAH to get this to run. Suggestions?

import arcpy

Practice_Sales1 = "Practice_Sales1"
Practice_Stops = "Practice_Stops"



import arcpy
fc = "y:/Practice_Sales1.shp"
field = "BOROUGH"
cursor = arcpy.SearchCursor(fc)

# Iterate through the rows in the cursor
for row in cursor:

    #Create Layer from the current row in the Practice_Sales1 file
     arcpy.MakeFeatureLayer_management("Practice_Sales.shp", "Sales_lyr", BLAH)

    # Select all features in Practice_Stops within 1000 feet of the current row in Practice_Sales1
    arcpy.SelectLayerByLocation_management(Practice_Stops, "WITHIN_A_DISTANCE", "Sales_lyr", "1000 Feet", "NEW_SELECTION", "NOT_INVERT")

    # Returns the # of selected features
    arcpy.GetCount_management(Practice_Stops)

    # Replace row value in COUNT field with 
    row.setValue("COUNT", arcpy.GetCount_management(Practice_Stops))

Answer 1

Here i used generation of a list of paired tuple of OID and Result of select by location operation.Then i created an update cursor to to update a filed named COUNT by the select by layer location result. You need to just create a field in Practice_Stops feature class named COUNT which is a type of short integer.Here inF is the layer will be updated with count of locational search and selectF is the feature class that will be counted.

    import arcpy
    arcpy.env.workspace = r'C:\Users\USER_NAME\Desktop\gissta\workspace'
    inF  = r'C:\Users\USER_NAME\Desktop\gissta\workspace\grid.shp'  #Practice_Stops
    selectF = r'C:\Users\USER_NAME\Desktop\gissta\workspace\schools_p.shp'  # "Practice_Sales.shp"

    pair = []
    pairID = []
    pairCNT = []

    def getCount(fc,countFc):
        arcpy.MakeFeatureLayer_management(fc,"sel_loc")
        arcpy.MakeFeatureLayer_management(countFc,"countF")
        curS = arcpy.da.SearchCursor("sel_loc",("OID@","SHAPE@"))
        for row in curS:
            S = row[1]
            arcpy.SelectLayerByLocation_management("countF","WITHIN_A_DISTANCE",S,"1000 Meters","NEW_SELECTION")
            cnt = str(arcpy.GetCount_management("countF"))
            pairID.append(row[0])
            pairCNT.append(cnt)
            print zip(pairID,pairCNT)
            pair.append(zip(pairID,pairCNT))

        del curS
        return pair
    getCount(inF, selectF)
    curU = arcpy.da.UpdateCursor(inF,("OID@","COUNT"))
    for row in curU:
        for i in pair:
            for x,y in i:
                print type(x)
                print type(row[0])
                print type(row[1])
                if (row[0] == x):
                    row[1]= y
                    curU.updateRow(row)
    del curU

Answer 2

The way I always handle this kind of thing is by making the entire FC a layer before entering the "for" loop. Then once inside the loop I use SelectLayerByAttribute on the the row based on OBJECTID or some other unique identifier. The following code should do what you need with a few changes. You will need to make sure the paths are all correct for your file system.

Edit: I have made a few changes that should hopefully make this easier to implement. You need to make sure you are working out of a GDB with true feature classes instead of using shape files. The where clause is structured for a gdb and won't work correctly on .shp files. You could do a little research on how to construct where clauses for shape files. Specifically the, AddFieldDelimeters tool would be helpful for this. I made one mistake in the original code in which I referenced a layer called 'Units'. This has been removed since obviously your project does not involve a layer with this name. That's what I get for copying and pasting code from my own projects :)

import arcpy
import os

arcpy.MakeFeatureLayer_management(r'Replace this sentence with the path to the Practice_Stops FC', 'Practice_Stops_lyr')

#You're original dataset
fc = r'Replace this senetence with the path to the Practice_Sales FC'  #you should import this into an FGDB to make it a true FC instead of using a .shp

#Create a scratch data workspace
try:
     arcpy.CreateFileGDB_management(r'Replace this sentence with a path to a location where you can store scratch data.', "ScratchFGD")
except:
     pass

#Create an object that stores the location for the scratch data
scratchFGD = r'Replace this sentence with the full path to the scratch geodatabase created in the previous step, make sure to include .gdb at the end' 

#Make a layer out of the the original FC
arcpy.MakeFeatureLayer_management(fc, 'Sales_lyr')

#Use an update cursor when there is a value you need to change in the attribute table
with arcpy.da.UpdateCursor('Sales_lyr', ["BOROUGH", "OBJECTID", "COUNT"]) as cursor:

     #For every row in the cursor, do the following
     for row in cursor:

          #Select the current row in the UpdateCursor
          arcpy.SelectLayerByAttribute_management('Sales_lyr', "NEW_SELECTION", "OBJECTID IN(" + str(row[1]) + ")")
          arcpy.AddMessage("Selection by attributes complete")
          print ("Selection by attributes complete")

          #Copy the selection to a new temporary feature
          arcpy.CopyFeatures_management('Sales_lyr', os.path.join(scratchFGD, "tempFeat"))
          arcpy.AddMessage("Copy complete")
          print ("Copy complete")

          #Make the temp feature a layer
          arcpy.MakeFeatureLayer_management(os.path.join(scratchFGD, "tempFeat"), "singleSalesRecord_lyr")
          arcpy.AddMessage("Feature layer created")
          print ("Feature layer created")

          # Select all features in Practice_Stops within 1000 feet of the current row in Practice_Sales1
          arcpy.SelectLayerByLocation_management('Practice_Stops_lyr', "WITHIN_A_DISTANCE", "singleSalesRecord_lyr", "1000 Feet", "NEW_SELECTION")
          arcpy.AddMessage("Select by Location complete")
          print ("Select by Location complete")

          # Returns the # of selected features
          practiceStopsCount = int(arcpy.GetCount_management('Practice_Stops_lyr').getOutput(0))
          arcpy.AddMessage("# of features within 1000 feet  = " + str(practiceStopsCount))
          print ("# of features within 1000 feet  = " + str(practiceStopsCount))

          # Replace row value in COUNT field with
          row[2] = practiceStopsCount
          cursor.updateRow(row)
          arcpy.AddMessage("Row Updated in Sales FC")
          print ("Row Updated in Sales FC"")

          #Clean up the temporary data
          arcpy.Delete_management(os.path.join(scratchFGD, "tempFeat"))
          arcpy.Delete_management('singleSalesRecord_lyr')
          arcpy.AddMessage("Deleted temp data")
          print ("Deleted temp data")

     del row

del cursor