import threading
from random import randint
from time import sleep
def print_number(number):
# Sleeps a random 1 to 10 seconds
rand_int_var = randint(1, 10)
sleep(rand_int_var)
print "Thread " + str(number) + " slept for " + str(rand_int_var) + " seconds"
thread_list = []
for i in range(1, 10):
# Instantiates the thread
# (i) does not make a sequence, so (i,)
t = threading.Thread(target=print_number, args=(i,))
# Sticks the thread in a list so that it remains accessible
thread_list.append(t)
# Starts threads
for thread in thread_list:
thread.start()
# This blocks the calling thread until the thread whose join() method is called is terminated.
# From http://docs.python.org/2/library/threading.html#thread-objects
for thread in thread_list:
thread.join()
# Demonstrates that the main process waited for threads to complete
print "Done"
# Python program to illustrate the concept
# of threading
# importing the threading module
import threading
def print_cube(num):
"""
function to print cube of given num
"""
print("Cube: {}".format(num * num * num))
def print_square(num):
"""
function to print square of given num
"""
print("Square: {}".format(num * num))
if __name__ == "__main__":
# creating thread
t1 = threading.Thread(target=print_square, args=(10,))
t2 = threading.Thread(target=print_cube, args=(10,))
# starting thread 1
t1.start()
# starting thread 2
t2.start()
# wait until thread 1 is completely executed
t1.join()
# wait until thread 2 is completely executed
t2.join()
# both threads completely executed
print("Done!")
Using a with statement alongwith the lock ensures the mutual exclusion. By exclusion, it is meant that at a time only one thread (under with statement) is allowed to execute the block of a statement.
The lock for the duration of intended statements is acquired and is released when the control flow exits the indented block
A thread is a separate flow of execution. This means that your program will have two things happening at once. But for most Python 3 implementations the different threads do not actually execute at the same time: they merely appear to.