The "Tree Manipulation and Restructuring" tutorial section has been
greatly expanded:
http://packages.python.org/DendroPy/tutorial/treemanips.html
Note that most functionality that used to be in "dendropy.treemanip"
has now been migrated as native methods of the Tree object. The
"dendropy.treemanip" functions will still be available for now, but
are soon to be deprecated.