def delete_edge(self, u, v=None):
if v is None: (u,v)=u
if self.degree(u)==1 or self.degree(v)==1:
DiGraph.delete_edge(self,u,v)
else:
raise NetworkXError(
"deleting interior edge %s-%s not allowed in tree"%(u,v))
if self.degree(u)==0: DiGraph.delete_node(self,u)
if self.degree(v)==0: DiGraph.delete_node(self,v)
def delete_edge(self, u, v=None):
if v is None: (u, v) = u
if self.degree(u) == 1 or self.degree(v) == 1:
DiGraph.delete_edge(self, u, v)
else:
raise NetworkXError(
"deleting interior edge %s-%s not allowed in tree" % (u, v))
if self.degree(u) == 0: DiGraph.delete_node(self, u)
if self.degree(v) == 0: DiGraph.delete_node(self, v)
def delete_node(self, n):
try:
if len(self.succ[n])+len(self.pred[n])==1: # allowed for leaf node
DiGraph.delete_node(self,n) # deletes adjacent edge too
else:
raise NetworkXError( \
"deleting interior node %s not allowed in tree"%(n))
except KeyError: # NetworkXError if n not in self
raise NetworkXError, "node %s not in graph"%n
def delete_node(self, n):
try:
if len(self.succ[n]) + len(
self.pred[n]) == 1: # allowed for leaf node
DiGraph.delete_node(self, n) # deletes adjacent edge too
else:
raise NetworkXError( \
"deleting interior node %s not allowed in tree"%(n))
except KeyError: # NetworkXError if n not in self
raise NetworkXError, "node %s not in graph" % n