python的多线程和多进程

#! /usr/bin/python
from threading import Thread
from multiprocessing import Process
import time
import sys
def my_counter():
    i = 0
    for _ in range(100000000):
        i = i + 1
    return True
def single_thread():
    start_time = time.time()
    for tid in range(3):
        my_counter()
    end_time = time.time()
    print("Total time: {}".format(end_time - start_time))
def mutiple_thread():
    thread_array = []
    start_time = time.time()
    for tid in range(3):
        t = Thread(target=my_counter)
        t.start()
        thread_array.append(t)
    for t in thread_array:
        t.join()
    end_time = time.time()
    print("Total time: {}".format(end_time - start_time))
def mutiple_porcess():
    process_array = []
    start_time = time.time()
    for pid in range(3):
        p = Process(target=my_counter)
        p.start()
        process_array.append(p)
    for p in process_array:
        p.join()
    end_time = time.time()
    print("Total time: {}".format(end_time - start_time))
if __name__ == '__main__':
    fun = sys.argv[1]
    if fun == 's':
        single_thread()
    elif fun == 'mt':
        mutiple_thread()
    else:
        mutiple_porcess()

HandeMacBook-Pro:MyTest HAN$ python process_thread.py s
Total time: 18.80652904510498
HandeMacBook-Pro:MyTest HAN$ python process_thread.py mt
Total time: 19.265798091888428
HandeMacBook-Pro:MyTest HAN$ python process_thread.py mp
Total time: 9.154397964477539