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I have data for several rain stations, i have averaged the data and given each county a value. Some counties have null values and I would like to pull the data from the all the bordering counties and use that to create an average for the null data county.

here is what i have so far

#Make Feature layer of counties that have 'NULL' for TCPT MNTM
#Select all counties that touch the boundaries of a single NULL county
#Average TCPT and MNTM values for selected counties
#Store average back in original counties layer

arcpy.MakeFeatureLayer_management(countyData,"badRows","\"MNTM\" = 'NULL'")
arcpy.MakeFeatureLayer_management(countyData,"goodRows","\"MNTM\" >= 0")

# a snippet i pulled from model builder and exported python code snippet

arcpy.SpatialJoin_analysis("Dissolved_Counties",climateData,"Average_Temperature_For_Texas_Counties","JOIN_ONE_TO_ONE","KEEP_ALL","""FIPS "FIPS" true true false 5 Text 0 0 ,First,#,Dissolved_Counties,FIPS,-1,-1;Shape_Length "Shape_Length" false true true 8 Double 0 0 ,First,#,Dissolved_Counties,Shape_Length,-1,-1;Shape_Area "Shape_Area" false true true 8 Double 0 0 ,First,#,Dissolved_Counties,Shape_Area,-1,-1;TPCP "TPCP" true true false 4 Long 0 0 ,Mean,#,Climate_Data_for_Texas,TPCP,-1,-1;MNTM "MNTM" true true false 4 Long 0 0 ,Mean,#,Climate_Data_for_Texas,MNTM,-1,-1""","INTERSECT","#","#")


i guess i am stuck here, i had before used the arcpy.GenerateNearTable_analysis to generate the values for the 4 nearest counties (but they werent always bordering and it needs to be bordering counties)

anyway if anyone would give me a little help i would much appreciate it

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A little more detail would help us understand your question. It might be that you want to interpolate a surface from your points and then get per-county averages with zonalstatisticsastable. This would eliminate null values.

Outside of that, your best bet might be:

SelectLayerByLocation_management (in_layer, {overlap_type}, {select_features}, {search_distance}, {selection_type})

There are a lot of selection_types, like "BOUNDARY_TOUCHES" and "SHARE_A_LINE_SEGMENT_WITH", that you might be able to use. Odds are good you'll have to cursor through all your null counties, applying a SelectLayerByLocation_management() based on each feature, and then figuring out a value to replace null with.

Truly automating evaluation of adjacent neighbors is fairly complicated, usually relying on topology. I'm not expert with this but I don't think there are pre-built rules for adjacency. You can check the The sample code below gives you an example of some of the most used topology functions. I wouldn't do this unless this was a big or recurring job. It's fairly expensive to learn and to run, at least in my fumbling hands.

PRMS_Topo = 'PRMS_Topo'
arcpy.CreateTopology_management(db_output_fd, PRMS_Topo, '')
arcpy.AddFeatureClassToTopology_management(PRMS_Topo, 'ICAs', '1', '1')
arcpy.AddRuleToTopology_management(PRMS_Topo, 'Must Not Overlap (Area)', 'ICAs', '', '', '')
arcpy.AddRuleToTopology_management (PRMS_Topo, 'Must Not Have Gaps (Area)', 'ICAs', '', '', '')
arcpy.ValidateTopology_management(PRMS_Topo, 'Full_Extent')

The spatial statistics toolbox could be of use, but would require some filtering to use for only adjacent/touching counties.

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