Python3, Why does this bypass GIL?

[Poet129]

I wrote this code to bypass GIL, but using things other than sleep seems to make it not work:

from timeit import timeit
from time import sleep
from threading import Thread
from os import cpu_count
openfile = open("TempFile.txt", "w")
openfile.write("")
openfile.close()
def run(x):
    sum = x + x
    sleep(1)
    openfile = open("TempFile.txt", "a")
    openfile.write(str(sum) + "\n")
    openfile.close()
def runCPU():
    x = 0
    threads = []
    while (x < cpu_count()):
        t = Thread(target=run, args=(x,))
        t.start()
        x += 1
        threads.append(t)
    for t in threads:
        t.join()
time = timeit(runCPU, number=1)
print(int(time))

 

[Sauron]

What makes you think this "bypasses" the GIL? If you have problems with the GIL you should just use multiprocessing or a python interpreter that isn't CPython.

[Poet129]

57 minutes ago, Sauron said:

What makes you think this "bypasses" the GIL? If you have problems with the GIL you should just use multiprocessing or a python interpreter that isn't CPython.

I've run it... but ok.

[Sauron]

7 minutes ago, Poet129 said:

I've run it... but ok.

You've run it and... what? If it was faster than just doing sleep x times that's because sleep doesn't actually do anything and other threads can be run while it's waiting.

[Poet129]

10 minutes ago, Sauron said:

You've run it and... what? If it was faster than just doing sleep x times that's because sleep doesn't actually do anything and other threads can be run while it's waiting.

Okay, that's probably right thanks.