How to use Spatial Criteria with ArcPy Data Access Search Cursor?

Question

The ArcGIS documentation for the Data Access Search Cursor states:

The records returned by SearchCursor can be constrained to match attribute criteria or spatial criteria.

But I can't see any example of how to specify spatial criteria when calling the search cursor. For this example I have a geometry and wish to constrain the results of the search cursor to only features which both intersect that geometry and meet other attribute criteria. e.g.

with arcpy.da.SearchCursor(fc,field_list,
                          "Admin_Code is null and shape intersects admin_area_geometry") 

I understand that I could perform a search cursor with the attribute query and then use the geometry intersects method but this would be slow to have to loop through each feature.

How can I specify both the spatial criteria when creating a search cursor?

Answer 1

I would suggest using a where clause to lessen the impact of pulling out geometry info that way you are not iterating through the entire table:

import arcpy

fc = 'c:/base/data.gdb/roads'
class_field = 'Road Class'
name_field = 'Name'

# Create an expression with proper delimiters
expression = arcpy.AddFieldDelimiters(fc, name_field) + ' = 2'

# Create a search cursor using an SQL expression
with arcpy.da.SearchCursor(fc, [class_field, name_field, SHAPE@],
                           where_clause=expression) as cursor:
    for row in cursor:
        # continue with logic