def _build_maze(edge_list):
    '''
        Generates a maze
    '''
    maze = {}  # empty dict to be returned + added to
    edge_points = []  # some edges have several edges.
    # iterate through the 2d list first.
    for i in edge_list:
        # assuming all edges have a key...
        key = i[0]
        edge = i[1]
        if key not in maze.keys():
            if edge not in maze.values():
                if edge != key:
                    edge_points.append(edge)
        else:
            maze[key] = set(edge_points)
            continue
        maze[key] = set(edge)

    return maze

edge_list = [['a','b'],
            ['a','c'],
            ['b','c'],
            ['b','d'],
            ['a','e'],
            ['e','d'],
            ['b','e']]


# should return ret_val = {'a': ('c', 'b', 'e'), 'b':('c', 'd', 'e'), 'e':('d')}
print(_build_maze(edge_list))