Getting "iteration not started" when using UpdateCursor / deleteRow()?

Question

I'm attempting to delete some features from a feature class using an arcpy.da.UpdateCursor. The line uc.deleteRow() throws an exception with the message iteration not started.

The where_clause is "item_no in (123,456,789)"; return records with a value in this field found in this comma-delimited list. Here is the where clause being passed in ITEM_NO in (1,8,9).

To remove the where_clause as a possible source of this problem, I hard-coded a single value into the where; "item_no = 123". This also threw the error.

If I change this to a searchCursor using the same parameters, three records are returned, as expected.

with arcpy.da.UpdateCursor(fc, "OBJECTID", where_clause=strWhere) as uc:
    for row in XYZ:
        try:
            uc.deleteRow()
        except Exception, e:
            print e

What am I doing wrong and how do I get around this?

Answer 1

Your UpdateCursor is called uc but you're iterating through XYZ

for row in XYZ:

As a result it hasn't started iterating through your cursor to be able to delete anything. You need to reference your cursor:

for row in uc: