"""
Example subclass of the Graph class.
"""
__author__ = """Aric Hagberg (hagberg@lanl.gov)"""
# Copyright (C) 2004-2009 by
# Aric Hagberg <hagberg@lanl.gov>
# Dan Schult <dschult@colgate.edu>
# Pieter Swart <swart@lanl.gov>
# All rights reserved.
# BSD license.
#
__docformat__ = "restructuredtext en"
from networkx import Graph
from networkx.exception import NetworkXException,NetworkXError
import networkx.convert as convert
from copy import deepcopy
class PrintGraph(Graph):
"""
Example subclass of the Graph class.
Prints activity log to file or standard output.
"""
def __init__(self, data=None, name='', file=None, **attr):
Graph.__init__(self, data=data,name=name,**attr)
if file is None:
import sys
self.fh=sys.stdout
else:
self.fh=open(file,'w')
def add_node(self, n, attr_dict=None, **attr):
Graph.add_node(self,n,attr_dict=attr_dict,**attr)
self.fh.write("Add node: %s\n"%n)
def add_nodes_from(self, nodes, **attr):
for n in nodes:
self.add_node(n, **attr)
def remove_node(self,n):
Graph.remove_node(self,n)
self.fh.write("Remove node: %s\n"%n)
def remove_nodes_from(self, nodes):
adj = self.adj
for n in nodes:
self.remove_node(n)
def add_edge(self, u, v, attr_dict=None, **attr):
Graph.add_edge(self,u,v,attr_dict=attr_dict,**attr)
self.fh.write("Add edge: %s-%s\n"%(u,v))
def add_edges_from(self, ebunch, attr_dict=None, **attr):
for e in ebunch:
u,v=e[0:2]
self.add_edge(u,v,attr_dict=attr_dict,**attr)
def remove_edge(self, u, v):
Graph.remove_edge(self,u,v)
self.fh.write("Remove edge: %s-%s\n"%(u,v))
def remove_edges_from(self, ebunch):
for e in ebunch:
u,v=e[0:2]
self.remove_edge(u,v)
def clear(self):
self.name = ''
self.adj.clear()
self.node.clear()
self.graph.clear()
self.fh.write("Clear graph\n")
def subgraph(self, nbunch, copy=True):
# subgraph is needed here since it can destroy edges in the
# graph (copy=False) and we want to keep track of all changes.
#
# Also for copy=True Graph() uses dictionary assignment for speed
# Here we use H.add_edge()
bunch =set(self.nbunch_iter(nbunch))
if not copy:
# remove all nodes (and attached edges) not in nbunch
self.remove_nodes_from([n for n in self if n not in bunch])
self.name = "Subgraph of (%s)"%(self.name)
return self
else:
# create new graph and copy subgraph into it
H = self.__class__()
H.name = "Subgraph of (%s)"%(self.name)
# add nodes
H.add_nodes_from(bunch)
# add edges
seen=set()
for u,nbrs in self.adjacency_iter():
if u in bunch:
for v,datadict in nbrs.iteritems():
if v in bunch and v not in seen:
dd=deepcopy(datadict)
H.add_edge(u,v,dd)
seen.add(u)
# copy node and graph attr dicts
H.node=dict( (n,deepcopy(d))
for (n,d) in self.node.iteritems() if n in H)
H.graph=deepcopy(self.graph)
return H
if __name__=='__main__':
G=PrintGraph()
G.add_node('foo')
G.add_nodes_from('bar',weight=8)
G.remove_node('b')
G.remove_nodes_from('ar')
print G.nodes(data=True)
G.add_edge(0,1,weight=10)
print G.edges(data=True)
G.remove_edge(0,1)
G.add_edges_from(zip(range(03),range(1,4)),weight=10)
print G.edges(data=True)
G.remove_edges_from(zip(range(03),range(1,4)))
print G.edges(data=True)
G=PrintGraph()
G.add_path(range(10))
print "subgraph"
H1=G.subgraph(range(4),copy=False)
H2=G.subgraph(range(4),copy=False)
print H1.edges()
print H2.edges()
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