class Box():

    def __init__(self, x=0, y=0, w=1, h=1):
        """Accept arguments to define our box, and store them."""
        self.x = x
        self.y = y
        self.w = w
        self.h = h

    def __repr__(self):
        return "Box(%s, %s, %s, %s)" % (self.x, self.y, self.w, self.h)


many_boxes = [Box() for i in range(5000)]

import svgwrite


def draw_boxes(boxes, fname, size):
    dwg = svgwrite.Drawing(fname, profile="full", size=size)
    # Draw all the boxes
    for box in boxes:
        dwg.add(
            dwg.rect(
                insert=(f"{box.x}cm", f"{box.y}cm"),
                size=(f"{box.w}cm", f"{box.h}cm"),
                fill="red",
            )
        )
    dwg.save()


draw_boxes(many_boxes, "lesson1.svg", ("5cm", "2cm"))