how to detect memory is freed by GC in python code example

Example 1: python clear memory

a = 10
print a 

del a       
print a      ## throws an error here because it's been deleted already.

Example 2: force garbage collection in python

import gc
gc.collect()

Example 3: python garbaze collection

import gc
gc.get_count()
gc.get_threshold()
gc.get_referrers(obj)