# DRILL: draw expanding/contracting circle

import drawSvg as draw

# Draw a frame of the animation
def draw_frame(r):
    d = draw.Drawing(250, 250, origin='center')
    d.append(draw.Circle(0, 0, r, fill='blue'))
    return d

# run the animation               
r = 0 # starting radius
R = 100 # ending radius
sign = 1
with draw.animate_jupyter(draw_frame, delay=0.01) as anim:
    while( r < R ):
        anim.draw_frame(r)
        r = r + 1