from time import sleep, time 
import gc 
 
def mem(way=1): 
 print time() 
 for i in range(10000000): 
  if way == 1: 
   pass 
  else: # way 2, 3 
   del i 
    
 print time() 
 if way == 1 or way == 2: 
  pass 
 else: # way 3 
  gc.collect() 
 print time() 
   
if __name__ == "__main__": 
 print "Test way 1: just pass" 
 mem(way=1) 
 sleep(20) 
 print "Test way 2: just del" 
 mem(way=2) 
 sleep(20) 
 print "Test way 3: del, and then gc.collect()" 
 mem(way=3) 
 sleep(20) 
  

Test way 1: just pass 
1426688589.47 
1426688590.25 
1426688590.25 
Test way 2: just del 
1426688610.25 
1426688611.05 
1426688611.05 
Test way 3: del, and then gc.collect() 
1426688631.05 
1426688631.85 
1426688631.95 

Test way 1: just pass 
1426689577.46 
1426689579.41 
1426689579.41 
Test way 2: just del 
1426689599.43 
1426689601.1 
1426689601.1 
Test way 3: del, and then gc.collect() 
1426689621.12 
1426689622.8 
1426689623.11 

ubuntu@my_machine:~$ ps -aux | grep test_mem 
Warning: bad ps syntax, perhaps a bogus '-'? See http://procps.sf.net/faq.html 
ubuntu 9122 10.0 6.0 270916 245564 pts/1 S+ 14:39 0:03 python test_mem.py 
ubuntu 9134 0.0 0.0 8104 924 pts/2 S+ 14:40 0:00 grep --color=auto test_mem 
ubuntu@my_machine:~$ ps -aux | grep test_mem 
Warning: bad ps syntax, perhaps a bogus '-'? See http://procps.sf.net/faq.html 
ubuntu 9122 10.0 6.0 270916 245564 pts/1 S+ 14:39 0:03 python test_mem.py 
ubuntu 9134 0.0 0.0 8104 924 pts/2 S+ 14:40 0:00 grep --color=auto test_mem 
ubuntu@my_machine:~$ ps -aux | grep test_mem 
Warning: bad ps syntax, perhaps a bogus '-'? See http://procps.sf.net/faq.html 
ubuntu 9122 11.6 0.1 30956 5608 pts/1 S+ 14:39 0:05 python test_mem.py 

while ((1)); do ps -aux | sort -n -k5,6 | grep my_script; free; sleep 5; done