output.txt

$ python s.py
Falling asleep
Falling asleep
Falling asleep
Falling asleep
Falling asleep
Falling asleep
Falling asleepFalling asleep

Falling asleep
Falling asleep
Waked up
Waked up
Waked up
Waked up
Waked up
Waked up
Waked upWaked up
Waked up

Waked up
3.00400996208 secs

s.py

from __future__ import absolute_import, division, print_function, unicode_literals

import threading
import time


def thread():
    print("Falling asleep")
    time.sleep(3)
    print("Waked up")

t1 = time.time()
threads = []
for i in range(10):
    th = threading.Thread(target=thread)
    th.start()
    threads.append(th)
for th in threads:
    th.join()
print(time.time()-t1, "secs")