Using SelectLayerByAttribute with list of values in ArcPy?

Question

I'm fairly new to python, so I'm having a little trouble with this. I want to iterate through a list of values, select the list values from a feature class, select from another feature class that intersects the first selection, and then calculate a field in the second selection based of the list index value. Here's the script I'm working on:

import arcpy
arcpy.env.workspace = r"C:workspace.gdb"

circuits = ["DC430", "DC431", "DC432"]

for i in range(len(circuits)):
    arcpy.SelectLayerByAttribute_management("Meters", "NEW_SELECTION", circuits[i])
    arcpy.SelectLayerByLocation_management("Parcels", "INTERSECT", "Meters", "", "NEW_SELECTION", "NOT_INVERT")
    arcpy.CalculateField_management("Parcels", "Circuit", "circuits[i]", "PYTHON_9.3", "")

How do I make this work the right way?

Answer 1

Iterate through your list of circuits and then create an SQL that matches the format you'd see in an ArcMap selection.

For text fields in a file geodatabase:

YOURFIELDNAME = 'FIELD VALUE'

Your code would be something like this:

import arcpy
arcpy.env.workspace = r"C:workspace.gdb"

circuits = ["DC430", "DC431", "DC432"]
circuitFieldName = "YOURFIELDNAMEHERE"

for circuit in circuits:
    sql = "{} = '{}'".format (circuitFieldName, circuit)
    arcpy.SelectLayerByAttribute_management("Meters", "NEW_SELECTION", sql)
    arcpy.SelectLayerByLocation_management("Parcels", "INTERSECT", "Meters")
    arcpy.CalculateField_management("Parcels", circuitFieldName, '"{}"'.format (circuit))