Solution: Remove an Edge

def remove_edge(graph, source, destination):
    """
    A function to remove an edge
    :param graph: A graph
    :param source: Source Vertex
    :param destination: Destination Vertex
    """
    if graph.V == 0:
        return graph
    if source >= graph.V or source < 0:
        return graph
    if destination >= graph.V or destination < 0:
        return graph
    temp = graph.graph[source]
    # If head node itself holds the key to be deleted
    if temp is not None:
        if temp.vertex == destination:
            graph.graph[source] = temp.next
            temp = None
            return
    while temp is not None:
        if destination == temp.vertex:
            break
        prev = temp
        temp = temp.next
    if temp is None:
        return
    # Set the new link 
    # from removed node's previous node to next node
    prev.next = temp.next
    temp = None
# Main program to test above function
if __name__ == "__main__":
    g = Graph(5)
    g.add_edge(0, 1)
    g.add_edge(0, 2)
    g.add_edge(1, 3)
    g.add_edge(1, 4)
    g.add_edge(2, 4)
    print("Before: ")
    g.print_graph()
    remove_edge(g, 1, 3)
    print("After: ")
    g.print_graph()