import sys a = [1,2,3] print(hex(id(a))) print(sys.getrefcount(a)) import ctypes def ref_count(address: int): return ctypes.c_long.from_address(address).value print(ref_count(id(a))) b= a print(hex(id(b))) print(ref_count(id(a))) # interesting b = None print(id(b)) # keep the id of a and see what happen after a is pointing to other value a_id = id(a) a = None print(ref_count(a_id)) print(ref_count(a_id))