Help understand loops

[snippsat]

I need to understand how printing 1 and 2 can be done at same time and not one after another.

You most use start() to spawn separate thread.
run() does not spawn a separate thread,it runs the thread function in the context of the current thread.

from threading import Thread
import time

def Loop1():
    while 1:
        time.sleep(2)
        print(1)

def Loop2():
    while 1:
        time.sleep(6)
        print(2)

process1 = Thread(target=Loop1)
process2 = Thread(target=Loop2)
process1.start()
process2.start()