How to Eat Memory using Python?

Question

Just for experiment, and Fun... I am trying to create an app that can \"Purposely\" consume RAM as much as we specify immediately. e.g. I want to consume 512 MB RAM, then the ap

Answer 1

One simple way might be:

some_str = ' ' * 512000000

Seemed to work pretty well in my tests.

Edit: in Python 3, you might want to use bytearray(512000000) instead.

Answer 2

Here is a version of markolopa's answer that worked for me:

import os
import psutil

PROCESS = psutil.Process(os.getpid())
MEGA = 10 ** 6
MEGA_STR = ' ' * MEGA


def pmem():
    try:
        tot, avail, percent, used, free, active, inactive, buffers = psutil.virtual_memory()
    except ValueError:
        tot, avail, percent, used, free, active, inactive, buffers, cached, shared = psutil.virtual_memory()
    tot, avail, used, free = tot / MEGA, avail / MEGA, used / MEGA, free / MEGA
    proc = PROCESS.memory_info()[1] / MEGA
    print('process = %s total = %s avail = %s used = %s free = %s percent = %s'
          % (proc, tot, avail, used, free, percent))


def alloc_max_array():
    i = 0
    ar = []
    while True:
        try:
            #ar.append(MEGA_STR)  # no copy if reusing the same string!
            ar.append(MEGA_STR + str(i))
        except MemoryError:
            break
        i += 1
    max_i = i - 1
    print('maximum array allocation:', max_i)
    pmem()


def alloc_max_str():
    i = 0
    while True:
        try:
            a = ' ' * (i * 10 * MEGA)
            del a
        except MemoryError:
            break
        i += 1
    max_i = i - 1
    _ = ' ' * (max_i * 10 * MEGA)
    print('maximum string allocation', max_i)
    pmem()

pmem()
alloc_max_str()
alloc_max_array()

Answer 3

You won't be able to allocate all the memory you can using constructs like

s = ' ' * BIG_NUMBER

It is better to append a list as in

a = []
while True:
    print len(a)
    a.append(' ' * 10**6)

Here is a longer code which gives more insight on the memory allocation limits:

import os
import psutil

PROCESS = psutil.Process(os.getpid())
MEGA = 10 ** 6
MEGA_STR = ' ' * MEGA

def pmem():
    tot, avail, percent, used, free = psutil.virtual_memory()
    tot, avail, used, free = tot / MEGA, avail / MEGA, used / MEGA, free / MEGA
    proc = PROCESS.get_memory_info()[1] / MEGA
    print('process = %s total = %s avail = %s used = %s free = %s percent = %s'
          % (proc, tot, avail, used, free, percent))

def alloc_max_array():
    i = 0
    ar = []
    while True:
        try:
            #ar.append(MEGA_STR)  # no copy if reusing the same string!
            ar.append(MEGA_STR + str(i))
        except MemoryError:
            break
        i += 1
    max_i = i - 1
    print 'maximum array allocation:', max_i
    pmem()

def alloc_max_str():
    i = 0
    while True:
        try:
            a = ' ' * (i * 10 * MEGA)
            del a
        except MemoryError:
            break
        i += 1
    max_i = i - 1
    _ = ' ' * (max_i * 10 * MEGA)
    print 'maximum string allocation', max_i
    pmem()

pmem()
alloc_max_str()
alloc_max_array()

This is the output I get:

process = 4 total = 3179 avail = 2051 used = 1127 free = 2051 percent = 35.5
maximum string allocation 102
process = 1025 total = 3179 avail = 1028 used = 2150 free = 1028 percent = 67.7
maximum array allocation: 2004
process = 2018 total = 3179 avail = 34 used = 3144 free = 34 percent = 98.9

Answer 4

You can allocate a huge amount of ram by executing :

while True:
    for i in range(0,100000000):
        Gig = 1024*1024*1024*2#A Gig multiplied by 2
        a = 787878788888888888888888888888 * (i * Gig)
        a = a * i
        print str(a)*2

I found this code freezing my pc in 5 minutes
Save it in a .pyw for background ram allocation
If it doesn't freeze your pc try increasing the a's value
To stop it quickly,Save this code in a .py file:

#First we send signals
os.system("TASKKILL /im pythonw.exe")
os.system("TASKKILL /im python.exe") 
print "Forcefull termination"
#Now we forcefully terminate
#pythonw.exe if running in idle or background
os.system("TASKKILL /im python.exe /f")
os.system("TASKKILL /im pythonw.exe /f")
os.system("pause")

Answer 5

x = bytearray(1024*1024*1000)

Eats about 1GB of memory