def path_nodes_to_edges(path):
    """
    Returns an ordered list of edges given a list of nodes
    
    Args:
        path - a path, as a sequence of nodes
        
    Returns: An ordered list of edges.
    """
    
    # Edge sequence initialization
    edge_sequence = []
    
    for i in range(len(path) - 1):
        edge_sequence.append((path[i], path[i+1]))
        
    return edge_sequence