def step(self, amt=1):
        "Make a frame of the animation"
        self.move_particles()
        if self.has_moving_emitters:
            self.move_emitters()
        self.start_new_particles()
        self.render_particles()
        if self.emitters == [] and self.particles == []:
            self.completed = True
def step ( self , amt = 1 ) : self . move_particles ( ) if self . has_moving_emitters : self . move_emitters ( ) self . start_new_particles ( ) self . render_particles ( ) if self . emitters == [ ] and self . particles == [ ] : self . completed = True
Make a frame of the animation