def area(pts,absolute=False):
    """
    Computes the clockwise area of the polygon defined by the points.
    Args:
        pts: list of (x,y) tuples. Assumes last and first vertex are different.
             Cannot handle if input points contain None coordinates.
        absolute: if true, returns the absolute value
    Returns:
        float representing the area
    """
    if pts[len(pts)-1] != pts[0]:
        pts.append(pts[0])
    a=[(pts[i+1][0]-pts[i][0])*(pts[i][1]+pts[i+1][1]) for i in range(len(pts)-1)]
    A=sum(a)/2
    if absolute:
        return abs(A)
    else:
        return A