Save backAndForth3.py or backAndForth3Flush.py to the new name backAndForth4.py. Add a triangular nose in the middle of the face in the makeFacefunction. Like the other features of the face, make sure the position of the nose is relative to the center parameter. Make sure the nose is included in the final list of elements of the face that get returned!

'''Test animation of a group of objects making a face. Combine the face elements in a function, and use it twice. Have an extra level of repetition in the animation.

This version may be wobbly and slow on some machines: Then see backAndForthFlush.py. '''

from graphics import * import time

def moveAll(shapeList, dx, dy): ''' Move all shapes in shapeList by (dx, dy).''' for shape in shapeList: shape.move(dx, dy)

def moveAllOnLine(shapeList, dx, dy, repetitions, delay): '''Animate the shapes in shapeList along a line. Move by (dx, dy) each time. Repeat the specified number of repetitions. Have the specified delay (in seconds) after each repeat. ''' for i in range(repetitions): moveAll(shapeList, dx, dy) time.sleep(delay)

def makeFace(center, win): '''display face centered at center in window win. Return a list of the shapes in the face. ''' head = Circle(center, 25) head.setFill("yellow") head.draw(win)

eye1Center = center.clone() # face positions are relative to the center eye1Center.move(-10, 5) # locate further points in relation to others eye1 = Circle(eye1Center, 5) eye1.setFill('blue') eye1.draw(win)

eye2End1 = eye1Center.clone() eye2End1.move(15, 0) eye2End2 = eye2End1.clone() eye2End2.move(10, 0) eye2 = Line(eye2End1, eye2End2) eye2.setWidth(3) eye2.draw(win)

mouthCorner1 = center.clone() mouthCorner1.move(-10, -10) mouthCorner2 = mouthCorner1.clone() mouthCorner2.move(20, -5) mouth = Oval(mouthCorner1, mouthCorner2) mouth.setFill("red") mouth.draw(win)

return [head, eye1, eye2, mouth]

def main(): win = GraphWin('Back and Forth', 300, 300) win.yUp() # make right side up coordinates!

rect = Rectangle(Point(200, 90), Point(220, 100)) rect.setFill("blue") rect.draw(win)

faceList = makeFace(Point(40, 100), win) faceList2 = makeFace(Point(150,125), win)

stepsAcross = 46 dx = 5 dy = 3 wait = .05 for i in range(3): moveAllOnLine(faceList, dx, 0, stepsAcross, wait) moveAllOnLine(faceList, -dx, dy, stepsAcross//2, wait) moveAllOnLine(faceList, -dx, -dy, stepsAcross//2, wait)

win.promptClose(win.getWidth()/2, 20)

main()