def mirror_x(clip, apply_to='mask'):
 return clip.fl_image((lambda f: f[:, ::(-1)]), apply_to=apply_to)

def mirror_x ( clip , apply_to = 'mask' ) : return clip . fl_image ( ( lambda f : f [ : , : : ( - 1 ) ] ) , apply_to = apply_to )
flips the clip horizontally .