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An ugly little script to test the affect of various object allocation 'strategies' in Python
#!/usr/bin/env python
import sys
import time
from random import randint
import gc
import subprocess
import os
from array import ArrayType
from ctypes import c_uint32, Structure
from contextlib import contextmanager
ARR_MAX = 10000000
def get_process_size():
cmd = ["/bin/ps","up",str(format(os.getpid()))]
p = subprocess.run(cmd, stdout=subprocess.PIPE)
output = p.stdout.decode().split("\n")[1]
fields = [a for a in output.split() if a]
return tuple(map(int,fields[4:6]))
def bytes_to_human(bytes):
for factor in ["B","KB","MB","GB","TB"]:
if bytes < 1024:
break
else:
bytes = bytes / 1024
return "{bytes:0.2f}{factor}".format(bytes=bytes,factor=factor)
def generate_point(x):
return x, x
@contextmanager
def timer(msg):
start = time.time()
print ("ENTER: {}".format(msg))
try:
yield
finally:
end = time.time() - start
print(" END: {} ({:0.2f}s)".format(msg, end))
start = get_process_size()
if sys.argv[1] == "list":
f = list(range(0,ARR_MAX))
elif sys.argv[1] == "atlist":
at = ArrayType("I", range(0,ARR_MAX))
elif sys.argv[1] == "ctypeslist":
intarr = c_uint32 * ARR_MAX
carr = intarr(*range(0,ARR_MAX))
elif sys.argv[1] == "tuplepoints":
f = [(x,x) for x in range(0,ARR_MAX)]
elif sys.argv[1] == "ctypespoints":
class POINT(Structure):
_fields_ = [("x", c_uint32),
("y", c_uint32)]
arr = POINT * ARR_MAX
arr2 = arr()
for i in range(0,ARR_MAX):
arr2[i] = POINT(i,i)
gc.collect()
end = get_process_size()
print (end[0] - start[0], end[1] - start[1])
@danudey

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danudey commented Jul 11, 2019

You can view an example graph showing the results from my testing. I had assumed that ctypes would be faster and more efficient, but it was not even remotely close in either dimension, so here we are.

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