from threading import Thread

# Example code by Akshar Raaj
# from http://agiliq.com/blog/2013/09/understanding-threads-in-python/

#define a global variable
some_var = 0

class IncrementThread(Thread):
    def run(self):
        #we want to read a global variable
        #and then increment it
        global some_var
        read_value = some_var
        print("some_var in {} before increment is {}"
              .format(self.name, read_value))
        some_var = read_value + 1 
        print("some_var in {} after increment is {}"
              .format(self.name, some_var))

def use_increment_thread(num_increments):
    threads = []
    # start some threads
    for i in range(num_increments):
        t = IncrementThread()
        threads.append(t)
        t.start()
    # wait for all threads to end
    for t in threads:
        t.join()
    print("After the modifications, some_var should have become {}"
          .format(num_increments))
    print("After the modifications, some_var is actually {}"
          .format(some_var))

if __name__ == '__main__':
    use_increment_thread(10)