ArcPy insertRow asking for a sequence of values

Question

I've got code that pulls the center point from a layer, and places it in a new feature class as part of a more complex analytical process.

I'm trying to get the centroid written to an in_memory feature class in order to use as a processing input for other stuff. There are no fields needed in addition to the SHAPE@XY token. Here's what I've got:

def get_extent_centroid(layer):
 desc = arcpy.Describe(layer)
 if desc.dataType in ['FeatureLayer', 'RasterLayer']:
 extent = desc.extent
 array = arcpy.Array()
 array.add(extent.lowerLeft)
 array.add(extent.lowerRight)
 array.add(extent.upperRight)
 array.add(extent.upperLeft)
 array.add(extent.lowerLeft)
 pg = arcpy.Polygon(array)
 centroid = pg.centroid
 return centroid
inlyr = arcpy.GetParameter(0)
center = get_extent_centroid(inlyr)
center_fc = arcpy.management.CreateFeatureclass("in_memory", "layercenter", "POINT", spatial_reference=arcpy.Describe(inlyr).spatialReference)
with arcpy.da.InsertCursor(center_fc, 'SHAPE@XY') as cursor:
 cursor.insertRow(center)

This results in:

TypeError: argument must be sequence of values

Which suggests that even though .centroid yields a valid point geometry, I have to do something more with it before sending it to the SHAPE@XY field?

Answer 1

So, apparently insertCursor demands a list object. With the following, the code works. I'll leave it here for posterity; if mods want to remove the question in case they find it too basic, that's fine too.

def get_extent_centroid(layer):
desc = arcpy.Describe(layer)
if desc.dataType in ['FeatureLayer', 'RasterLayer']:
 extent = desc.extent
 array = arcpy.Array()
 array.add(extent.lowerLeft)
 array.add(extent.lowerRight)
 array.add(extent.upperRight)
 array.add(extent.upperLeft)
 array.add(extent.lowerLeft)
 pg = arcpy.Polygon(array)
 centroid = pg.centroid
 return centroid
inlyr = arcpy.GetParameter(0)
center = get_extent_centroid(inlyr)
center_fc = arcpy.management.CreateFeatureclass("in_memory", "layercenter", "POINT", spatial_reference=arcpy.Describe(inlyr).spatialReference)
# fixed part
center_row = [(center.Y, center.X)]
with arcpy.da.InsertCursor(center_fc, 'SHAPE@XY') as cursor:
cursor.insertRow(center_row)

• Vince: But first you ought to capture that SpatialReference in a variable, and pass it into the Polygon constructor. While optional, failure to pass in a spatial reference can corrupt your coordinates, and possibly the geometry itself, but only when it is rewritten to conform to the target SpatialReference, during the insertRow.
• Vince: Not that FeatureToPoint would do this faster.
• Bera: Accept your answer, one less unanswered question