from __future__ import print_function

"""Classes for tracking the coordinates and computing
some properties of rectangles."""

class Vector:
	"""Represents a vector in 2-D space."""

	def __init__(self, x, y):
		self.x = x
		self.y = y

	def add(self, dx, dy):
		"""Move this vector by given offset."""
		self.x += dx
		self.y += dy

class Rectangle:
	"""Represents a rectangle in 2-D space.

	Attributes: width, height, corner."""

	def __init__(self, x, y, width, height):
		self.corner = Vector(x, y)
		self.width = width
		self.height = height

	def shift(self, dx, dy):
		"""Move this rectangle by given offset."""
		self.corner.add(dx, dy)

	def offset(self, dx, dy):
		"""Return new rectangle shifted by given offset."""
		r = Rectangle(self.corner.x, self.corner.y,
				self.width, self.height)
		r.shift(dx, dy)
		return r

	def area(self):
		"""Return area of rectangle."""
		return self.width * self.height

	def as_string(self):
		return "([%.3f, %.3f], w=%.3f, h=%.3f)" % (
				self.corner.x, self.corner.y,
				self.width, self.height)

if __name__ == "__main__":
	print("create r1")
	r1 = Rectangle(10, 20, 30, 40)
	print("r1:", r1.as_string(), "area:", r1.area())

	print("shift r1 by -10, -20")
	r1.shift(-10, -20)
	print("r1 shifted:", r1.as_string())

	print("offset r1 by 100, 100")
	r2 = r1.offset(100, 100)
	print("r1 after offset:", r1.as_string())
	print("r2 after offset:", r2.as_string())