Let's use the old way first:
fc = r"some datasource"
arcpy.AddField_management(fc, fieldName1, "DOUBLE",
fieldPrecision, fieldScale)
arcpy.AddField_management(fc, fieldName2, "DOUBLE",
fieldPrecision, fieldScale)
# Calculate centroid
arcpy.CalculateField_management(fc, fieldName1,
"!SHAPE.CENTROID.X!",
"PYTHON_9.3")
arcpy.CalculateField_management(fc, fieldName2,
"!SHAPE.CENTROID.Y!",
"PYTHON_9.3")
So here we create the field and then perform a calculation on the data set to get the X/Y centroid of the data.At 10.2.1 you can clean this up and just do the following:
fc = "some dataset"
arcpy.AddGeometryAttributes_management(fc, "CENTROID")
With just two lines of code, we did what took multiple line previously to 10.2.1. The Add Geometry Attributes tool is a time saver, and makes life just a tad easier. It's a convenient tool that allows for quick addition of geometry attributes.
Check out more about this tool here.
Enjoy