I can create a centroid latitude field in ArcMap10.1 using "Calculate Geometry..." in the attribute table, but when I try the same thing using: arcpy.CalculateField_management(bins_WGS84, "cent_lat", "!SHAPE.CENTROID.Y!", "PYTHON_9.3"),
I get the following error: arcgisscripting.ExecuteError: ERROR 000539: Error running expression: GPVARIANTOBJECT0.CENTROID.Y. It only happens occasionally, but kills my script and costs me lots of time/data. On the particular dataset I'm testing, it happens about 10 rows in, although the geometry looks fine and Arcmap doesn't complain when finding the centroid.
I know it is possible, because it's working for the same dataset in ArcMap, however, this action does not show up in the Results window.