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Please help resolve the following challenge: I have two feature classes, which have the same number of polygon features, that when overlaid form concentric "rings." I need to erase the inner circle from the outer circle for each feature, matching them by their record ID. So, if both feature classes 1 and 2 have records A, B, and C, I want to erase the polygon of Record A in FC2 from Record A in FC1, RecordB in FC2 from Record B in FC1, etc.

ArcGIS' Erase function will only take the entirety of the feature class and erase from them - I can't find a way to link up records by their feature ID.

  I'm working with Arc10.1 with all licenses.

EDIT: The following is a draft of code I'm having trouble editing. I'm a novice Python-ista and my issue is in developing/managing two SearchCursors at the same time? ...any takers to help me get this rolling?

import os
import sys
import arcpy
from arcpy import env
import time

workspace = "C:\\BOEM\\pt_buff3\\"


fileList = []
buffs = workspace+"buffer.gdb"
directorypath = buffs

#create new results_feature class

for dirpath, dirnames, buffs in arcpy.da.Walk(directorypath,
                                              datatype="FeatureClass",
                                              type="Polygon"):
    for buff in buffs:
        if buff.endswith("d4"):#buffbits=buff.split('_')
            #inputfc4 = buff.endswith("d4")
            inputfc4bit=inputfc4.split('_')
 
        inputfc3 = buff.endswith("d3")
        inputfc3bit=inputfc3.split('_')

        if inputfc4bit[2]== inputfc3bit[2]:
            #convert inputfc4 and inputfc3 to feature layers
            #MakeFeatureLayer_management(in_feat, out_layer, [where_clause}, {workspace},{field_infp})
            in_feat4 = buffs+inputfc4
            out_feat4 = in_feat4+"_lyr"
            in_feat3 = buffs+inputfc3
            out_feat3 = in_feat3+"_lyr"
            arcpy.MakeFeatureLayer_management(in_feat4,out_feat4)
            arcpy.MakeFeatureLayer_management(in_feat3,out_feat3)
 
            #searchcursor for APR16ID in inputfc4 to match APR16Id in inputfc3
            #SearchCursor(in_table, field_names,{where_clause},"","","")
            #where_clause= """ "APR16_ID" = """ + 
 
            record_fc4 = arcpy.SearchCursor(out_feat4, "APR16_ID", "","","")
            record_fc3 = arcpy.SearchCursor(out_feat3, "APR16_ID","","","")
            if record_fc3.APR16_ID == record_fc4.APR16_ID:
                #select layer by attribute
                #SelectLayerByAttribute_management(in_layer, {selection_type}, {where_clause})
                in_layer3 = out_feat3
                in_layer4 = out_feat4
                arcpy.SelectLayerByAttribute_management(in_layer3, "NEW_SELECTION","","")
                arcpy.SelectLayerByAttrbiute_management(in_layer4, "NEW_SELECTION","","")
            #erase funtion
            erase_from = in_layer4
            erase_feat = in_layer3
            results_fc = workspace+"donuts_output.gdb"

            arcpy.Erase_analysis(erase_from, erase_feat, results_fc,'')                    
             
            
            `

This is the challenge: I have two feature classes, which have the same number of polygon features, that when overlaid form concentric "rings." I need to erase the inner circle from the outer circle for each feature, matching them by their record ID. So, if both feature classes 1 and 2 have records A, B, and C, I want to erase the polygon of Record A in FC2 from Record A in FC1, RecordB in FC2 from Record B in FC1, etc.

ArcGIS' Erase function will only take the entirety of the feature class and erase from them - I can't find a way to link up records by their feature ID. I'm working with Arc10.1 with all licenses.

LATEST EDITS: I've replaced the useless code from before with this revised snippet below, but now I need a bit of guidance - I can't find where in here that I am over-writing the output. It works! However the script leaves me with a single donut feature output. Can you help me spot my error?

#Test script: select record from a VTR and erase it from another, matching selected record

import os
import sys
import arcpy
from arcpy import env
import time

#Set overwrote output
arcpy.env.overwriteOutput = True
print arcpy.env.overwriteOutput

workspace = "C:\\BOEM\\pt_buff3\\"


fileList = []
buffersd4 = []
buffersd3 = []
recordID3 = []
recordID4 = []

buffs = workspace+"buffer.gdb"
directorypath = buffs

#create new results_feature class

for dirpath, dirnames, buffs in arcpy.da.Walk(directorypath,
                                              datatype="FeatureClass",
                                              type="Polygon"):
for buff in buffs:
     
    if buff.endswith(str("d4")):
       # buffersd4.append(buff)
        #print buffersd4
       print buff
       buffbits4=buff.split('_')
       print buffbits4[2]
       buffersd4.append(buff)
       field = ['APR16_ID']
       APR16_ID = [row[0] for row in arcpy.da.SearchCursor(workspace+"buffer.gdb\\"+buff,(field))]
       print APR16_ID
       for ID4 in APR16_ID:
           ID4split = ID4.split('_')
           selectID4 = ID4split[1]
           #print selectID4

    if buff.endswith(str("d3")):
       # buffersd4.append(buff)
        #print buffersd4
       print buff
       buffbits3=buff.split('_')
       print buffbits3[2]
       buffersd3.append(buff)
       field = ['APR16_ID']
       APR16_ID = [row[0] for row in arcpy.da.SearchCursor(workspace+"buffer.gdb\\"+buff,(field))]
       print APR16_ID
       for ID3 in APR16_ID:
           ID3split = ID3.split('_')
           selectID3 = ID3split[1]
          # print selectID3
print selectID4
print selectID3
if selectID4 == selectID3:
    print "yay they match!"
     
    #make feature layer of feature d4 for FCs in buffersd4:
    for fc in buffersd4:
        in_feat=workspace+"buffer.gdb\\"+fc
        out_layer4= fc+"_lyr"
        arcpy.MakeFeatureLayer_management(in_feat,out_layer4)
        print arcpy.GetMessages()
    #select record in fc_layer
        #where_clause4=""" "APR16_ID" = """ + str(selectID4)
        where_clause4=""" "APR16_ID" = """ + "'"+ID4+"'"
        arcpy.SelectLayerByAttribute_management(out_layer4,"NEW_SELECTION",where_clause4)
        print arcpy.GetMessages()
       
    #make feature layer of feature d3
    for fc in buffersd3:
        in_feat=workspace+"buffer.gdb\\"+fc
        out_layer3= fc+"_lyr"
        arcpy.MakeFeatureLayer_management(in_feat,out_layer3)
        print arcpy.GetMessages()
    #select record in fc_layer
        #where_clause3=""" "APR16_ID" = """ + str(selectID3)
        where_clause3=""" "APR16_ID" = """ + "'"+ID3+"'"
        arcpy.SelectLayerByAttribute_management(out_layer3,"NEW_SELECTION",where_clause3)
        print arcpy.GetMessages()
    
 #execute Erase function(erase d3 from d4)
        out_feat = "C:\\BOEM\\Donuts\\donuts_output.gdb\\"+"donut_d4_"+ID4
        arcpy.Erase_analysis(out_layer4, out_layer3,out_feat,"")
        print arcpy.GetMessages()
         
    print "done rolling through records in this feature class."

    print "done going through the buffers in the fGDB"
     

    #celebrate
   
         
         
        
           
            `

Any suggestions are very much appreciated. I'm working with Arc10.1 with all licenses.

I'm working with Arc10.1 with all licenses.

EDIT: The following is a draft of code I'm having trouble editing. I'm a novice Python-ista and my issue is in developing/managing two SearchCursors at the same time? ...any takers to help me get this rolling?

import os
import sys
import arcpy
from arcpy import env
import time

workspace = "C:\\BOEM\\pt_buff3\\"


fileList = []
buffs = workspace+"buffer.gdb"
directorypath = buffs

#create new results_feature class

for dirpath, dirnames, buffs in arcpy.da.Walk(directorypath,
                                              datatype="FeatureClass",
                                              type="Polygon"):
    for buff in buffs:
        if buff.endswith("d4"):#buffbits=buff.split('_')
            #inputfc4 = buff.endswith("d4")
            inputfc4bit=inputfc4.split('_')

        inputfc3 = buff.endswith("d3")
        inputfc3bit=inputfc3.split('_')

        if inputfc4bit[2]== inputfc3bit[2]:
            #convert inputfc4 and inputfc3 to feature layers
            #MakeFeatureLayer_management(in_feat, out_layer, [where_clause}, {workspace},{field_infp})
            in_feat4 = buffs+inputfc4
            out_feat4 = in_feat4+"_lyr"
            in_feat3 = buffs+inputfc3
            out_feat3 = in_feat3+"_lyr"
            arcpy.MakeFeatureLayer_management(in_feat4,out_feat4)
            arcpy.MakeFeatureLayer_management(in_feat3,out_feat3)

            #searchcursor for APR16ID in inputfc4 to match APR16Id in inputfc3
            #SearchCursor(in_table, field_names,{where_clause},"","","")
            #where_clause= """ "APR16_ID" = """ + 

            record_fc4 = arcpy.SearchCursor(out_feat4, "APR16_ID", "","","")
            record_fc3 = arcpy.SearchCursor(out_feat3, "APR16_ID","","","")
            if record_fc3.APR16_ID == record_fc4.APR16_ID:
                #select layer by attribute
                #SelectLayerByAttribute_management(in_layer, {selection_type}, {where_clause})
                in_layer3 = out_feat3
                in_layer4 = out_feat4
                arcpy.SelectLayerByAttribute_management(in_layer3, "NEW_SELECTION","","")
                arcpy.SelectLayerByAttrbiute_management(in_layer4, "NEW_SELECTION","","")
            #erase funtion
            erase_from = in_layer4
            erase_feat = in_layer3
            results_fc = workspace+"donuts_output.gdb"

            arcpy.Erase_analysis(erase_from, erase_feat, results_fc,'')                    
            
            
            `