print arcpy.Describe('seacoast').extent arcpy.env.workspace = r'E:\project\forumhelp'
>>> print arcpy.Describe("sourcearea").extent
2626051.8 185544.48 2626576.5 186112.94 NaN NaN NaN NaN
>>> # moved a vertex to the left, saved
>>> print arcpy.Describe("sourcearea").extent
2625867.4387207 185544.480102539 2626576.50012207 186112.940124512 NaN NaN NaN NaN