It's been 24 hours so Joe must have another Python question...
When I run the following in the python window it runs just fine:
with arcpy.da.SearchCursor(fc,fields) as rows:
... streets = [row[1] for row in rows]
... street = ",".join(["'{}'".format(s) for s in streets])
... num = int(row[0])
... max = num + 10
... min = num - 10
... where = "FullStreet = ({}) AND numeric_hn <=({}) AND numeric_hn >= ({})".format(street,max,min)
... arcpy.SelectLayerByAttribute_management ("apLayer","ADD_TO_SELECTION",where)
I should add that I set fc = a given layer file in the arcmap session and fields is set to a list of two fields in the order of ["numeric_hn", "FullStreet"]
