कोडिंग कार्यप्रवाह · बहुभुज का दिशायुक्त क्षेत्रफल

def signed_double_area(points):
    if type(points) not in (list, tuple) or not 3 <= len(points) <= 256:
        raise ValueError("polygon.count")
    for p in points:
        if type(p) not in (list, tuple) or len(p) != 2 or any(type(v) is not int or abs(v) > 10**6 for v in p):
            raise ValueError("polygon.coordinate")
    return sum(a[0]*b[1]-a[1]*b[0] for a,b in zip(points, points[1:]+points[:1]))