Did you try capitalizing the "M" in "XMax"? I think it's supposed to be:

print desc.extent.XMax

instead of

print desc.extent.Xmax

according to the documentation. Of course that makes me wonder how your first code snippet worked. Either way, give it a shot!

Try capitalizing the "M" in "XMax". I think it's supposed to be:

print desc.extent.XMax

instead of

print desc.extent.Xmax

according to the documentation. Of course that makes me wonder how your first code snippet worked.