old_contents: #!/usr/bin/python
  # encoding=utf8
  
  from __future__ import print_function
  # Author: OMKAR PATHAK
  
  # We can use Python's dictionary for constructing the graph
  
  class AdjacencyList(object):
      def __init__(self):
          self.List = {}
  
      def addEdge(self, fromVertex, toVertex):
          # check if vertex is already present
          if fromVertex in self.List.keys():
              self.List[fromVertex].append(toVertex)
          else:
              self.List[fromVertex] = [toVertex]
  
      def printList(self):
          for i  in self.List:
              print((i,'->',' -> '.join([str(j) for j in self.List[i]])))
  
  if __name__ == '__main__':
      al = AdjacencyList()
      al.addEdge(0, 1)
      al.addEdge(0, 4)
      al.addEdge(4, 1)
      al.addEdge(4, 3)
      al.addEdge(1, 0)
      al.addEdge(1, 4)
      al.addEdge(1, 3)
      al.addEdge(1, 2)
      al.addEdge(2, 3)
      al.addEdge(3, 4)
  
      al.printList()
  
      # OUTPUT:
      # 0 -> 1 -> 4
      # 1 -> 0 -> 4 -> 3 -> 2
      # 2 -> 3
      # 3 -> 4
      # 4 -> 1 -> 3
  
new_contents: #!/usr/bin/python
  # encoding=utf8
  
  from __future__ import print_function
  # Author: OMKAR PATHAK
  
  # We can use Python's dictionary for constructing the graph.
  
  class AdjacencyList(object):
      def __init__(self):
          self.List = {}
  
      def addEdge(self, fromVertex, toVertex):
          # check if vertex is already present
          if fromVertex in self.List.keys():
              self.List[fromVertex].append(toVertex)
          else:
              self.List[fromVertex] = [toVertex]
  
      def printList(self):
          for i  in self.List:
              print((i,'->',' -> '.join([str(j) for j in self.List[i]])))
  
  if __name__ == '__main__':
      al = AdjacencyList()
      al.addEdge(0, 1)
      al.addEdge(0, 4)
      al.addEdge(4, 1)
      al.addEdge(4, 3)
      al.addEdge(1, 0)
      al.addEdge(1, 4)
      al.addEdge(1, 3)
      al.addEdge(1, 2)
      al.addEdge(2, 3)
      al.addEdge(3, 4)
  
      al.printList()
  
      # OUTPUT:
      # 0 -> 1 -> 4
      # 1 -> 0 -> 4 -> 3 -> 2
      # 2 -> 3
      # 3 -> 4
      # 4 -> 1 -> 3
  
subject: Update graph.py (#809)