def get_installed_pypackages():
    return {p.project_name.lower(): p for p in pkg_resources.working_set}
def getR(self):
        # x 分量與 y 分量
        x = self.p1.x - self.p2.x
        y = self.p1.y - self.p2.y
        return math.sqrt(x * x + y * y)