def new_edge_weight(vertex, line):
    """
    Compute the weight of the splitted edge of geometry *line* and original
    vertex row *vertex*.

    Parameters
    ----------
    vertex: Series
        Row of the dataframe *vertices*.
    line: LineString
        One of the two geometries of the splitted edge.

    Returns
    -------
    float
        Weight of the new vertex.
    """
    return vertex['weight'] * line.length / vertex['geometry'].length
