import sys
a = [1,2,3]
print(hex(id(a))) # a is passing into a function, so a counter become 2, can't use normal python to check
print(sys.getrefcount(a))
# write a function with c code to check
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))
