[Spot] How to free the memory of an automaton in spot's Python API?

Hi, I'm building some automatons using spot's python interface. Simply, codes like: for i in n: temp_aut = spot.automaton(aut.to_str()) # copy an automaton ...something del temp_aut But I found that whenever it enters a new loop, the memory of the automaton assigned to temp_aut is not freed. And it leads to a memory overflow. I thought this might be solved with 'delete temp_aut' in the C++ version spot, but in the python interface 'del temp' doesn't seem to work. Is there any interface in Python or other operations to make it possible?