9.4. Taxon.__cmp__(): Compare taxa
in phylogenetic order
This method is called when the usual Python cmp() function is applied to two Taxon instances. It orders them using the
phylogenetic key.
xnomo3.py
# - - - T a x o n . _ _ c m p _ _ - - -
def __cmp__ ( self, other ):
"""Compare two taxa, order them phylogenetically.
[ self and other are Taxon instances ->
if self occurs before other in phylogenetic order ->
return -1
else if self is the same taxon as other ->
return 0
else -> return 1 ]
"""
return cmp ( self.txKey, other.txKey )
