Illustration for python memory fragmentation issue

mem_hog.py

#!/usr/bin/python3
import random
import time

MAX_HOG = 1000*1000

def sparse(something):
    for element in something:
        victim = element["big"]
        element["big"] = None
        del victim

def hog():
    res=[]
    for counter in range(0,MAX_HOG):
        res.append({
            "small": random.random(),
            "big": "%3500f" % random.random()
        })
    return res

def print_mem_footprint(something):
    sum_all = 0
    dicts = 0
    big = 0
    small = 0
    for element in something:
        dicts += element.__sizeof__()
        big += element["big"].__sizeof__()
        small += element["small"].__sizeof__()
    sum_all = something.__sizeof__() + dicts + big + small
    print("List size: %s" % something.__sizeof__())
    print("Total dicts size: %s" % dicts)
    print("Total small objects size: %s" % small)
    print("Total big objects size: %s" % big)
    print("Sum of above: %s" % sum_all)

    
        
if __name__ == '__main__':
    res=hog()
    print("Memory after hogging")
    print_mem_footprint(res)
    sparse(res)
    print ("-" * 60)
    print("Memory after sparsing")
    print_mem_footprint(res)
    print("Press Ctrl-C to exit")   
    while True:
        time.sleep(3600)