def _update(self, frame_no):
        # Take a copy in case a new system is added to the list this iteration.
        for system in copy(self._active_systems):
            if len(system.particles) > 0 or system.time_left > 0:
                system.update()
            else:
                self._active_systems.remove(system)
dataset/ETHPy150Open peterbrittain/asciimatics/asciimatics/particles.py/ParticleEffect._update/original