def shift_in_from_bottom(image):
"""
Creates an animation where "image" is shifted from bottom
of the display up in to the center of the display.
"""
for i in reversed(range(DISPLAY_WIDTH + 1)):
yield Image.shift_down(image, i)
def shift_out_to_bottom(image):
"""
Creates an animation where "image" is shifted from center
of display out of the screen downwards.
"""
for i in range(DISPLAY_WIDTH + 1):
yield Image.shift_down(image, i)
