Source Code for Module networkx.readwrite.graphml

  1  """ 
  2  Read graphs in GraphML format. 
  3  http://graphml.graphdrawing.org/ 
  4   
  5  """ 
  6  # Original author: D. Eppstein, UC Irvine, August 12, 2003. 
  7  # The original code at http://www.ics.uci.edu/~eppstein/PADS/ is public domain. 
  8  __author__ = """Aric Hagberg (hagberg@lanl.gov)""" 
  9  __date__ = """""" 
 10  __credits__ = """""" 
 11  __revision__ = "" 
 12  #    Copyright (C) 2004-2007 by  
 13  #    Aric Hagberg <hagberg@lanl.gov> 
 14  #    Dan Schult <dschult@colgate.edu> 
 15  #    Pieter Swart <swart@lanl.gov> 
 16  #    Distributed under the terms of the GNU Lesser General Public License 
 17  #    http://www.gnu.org/copyleft/lesser.html 
 18   
 19  import networkx 
 20  from networkx.exception import NetworkXException, NetworkXError 
 21  from networkx.utils import _get_fh 
 22           
 23 -def read_graphml(path): 
 24      """Read graph in GraphML format from path. 
 25      Returns an XGraph or XDiGraph.""" 
 26      fh=_get_fh(path,mode='r')         
 27      G=parse_graphml(fh) 
 28      return G 
 29           
 30 -def parse_graphml(lines): 
 31      """Read graph in GraphML format from string. 
 32      Returns an XGraph or XDiGraph.""" 
 33      context = [] 
 34      G=networkx.XDiGraph() 
 35      defaultDirected = [True] 
 36           
 37      def start_element(name,attrs): 
 38          context.append(name) 
 39          if len(context) == 1: 
 40              if name != 'graphml': 
 41                  raise GraphFormatError, \ 
 42                        'Unrecognized outer tag "%s" in GraphML' % name 
 43          elif len(context) == 2 and name == 'graph': 
 44              if 'edgedefault' not in attrs: 
 45                  raise GraphFormatError, \ 
 46                        'Required attribute edgedefault missing in GraphML' 
 47              if attrs['edgedefault'] == 'undirected': 
 48                  print "undirected" 
 49                  defaultDirected[0] = False 
 50          elif len(context) == 3 and context[1] == 'graph' and name == 'node': 
 51              if 'id' not in attrs: 
 52                  raise GraphFormatError, 'Anonymous node in GraphML' 
 53              G.add_node(attrs['id']) 
 54          elif len(context) == 3 and context[1] == 'graph' and name == 'edge': 
 55              if 'source' not in attrs: 
 56                  raise GraphFormatError, 'Edge without source in GraphML' 
 57              if 'target' not in attrs: 
 58                  raise GraphFormatError, 'Edge without target in GraphML' 
 59              G.add_edge(attrs['source'], attrs['target'],attrs.get('id'))   
 60              # no mixed graphs in NetworkX 
 61              # handle mixed graphs by adding two directed 
 62              # edges for an undirected edge in a directed graph  
 63              if attrs.get('directed')=='false': 
 64                  if defaultDirected[0]: 
 65                      G.add_edge(attrs['target'], attrs['source'],attrs.get('id')) 
 66                   
 67      def end_element(name): 
 68          context.pop() 
 69           
 70      import xml.parsers.expat 
 71      p = xml.parsers.expat.ParserCreate() 
 72      p.StartElementHandler = start_element 
 73      p.EndElementHandler = end_element 
 74      for line in lines: 
 75          p.Parse(line) 
 76      p.Parse("", 1) 
 77   
 78      if defaultDirected[0]: 
 79          return G 
 80      else: 
 81          return G.to_undirected() 
 82   
 83   
 84 -def _test_suite(): 
 85      import doctest 
 86      suite = doctest.DocFileSuite('tests/readwrite/graphml.txt', 
 87                                   package='networkx') 
 88      return suite 
 89   
 90  if __name__ == "__main__": 
 91      import os  
 92      import sys 
 93      import unittest 
 94      if sys.version_info[:2] < (2, 4): 
 95          print "Python version 2.4 or later required for tests (%d.%d detected)." %  sys.version_info[:2] 
 96          sys.exit(-1) 
 97      # directory of networkx package (relative to this) 
 98      nxbase=sys.path[0]+os.sep+os.pardir 
 99      sys.path.insert(0,nxbase) # prepend to search path 
100      unittest.TextTestRunner().run(_test_suite()) 
101