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Python threading active_count() Method with Example

Python threading.active_count() Method: In this tutorial, we will learn about the active_count() method of threading Module in Python with its usage, syntax, and examples. By Hritika Rajput Last updated : April 23, 2023

Python threading.active_count() Method

The threading.active_count() is an inbuilt method of the threading module, it is used to return the number of Thread objects that are active at any instant.

Module

The following module is required to use active_count() method:

import threading

Syntax

The following is the syntax of active_count() method:

active_count()

Parameter(s)

The following are the parameter(s):

• None

Return Value

The return type of this method is <class 'int'>, it returns the number of active Thread class objects at any instant.

Example of threading.active_count() Method in Python

# Python program to explain the use of 
# active_count() method in Threading Module

import time
import threading

def thread_1(i):
    time.sleep(2)
    print("Number of active threads:", threading.active_count())
    print('Value by Thread 1:', i)

def thread_2(i):
    time.sleep(5)
    print("Number of active threads:", threading.active_count())
    print('Value by Thread 2:', i)
    
def thread_3(i):
    print("Number of active threads:", threading.active_count())
    print("Value by Thread 3:", i)
    
# Creating sample threads 
thread1 = threading.Thread(target=thread_1, args=(1,))
thread2 = threading.Thread(target=thread_2, args=(2,))
thread3 = threading.Thread(target=thread_3, args=(3,))

print("Number of active threads in the starting:", threading.active_count())
print("The active threads in the starting is 1 which is the main thread that executes till the program runs")

# Starting the threads
thread1.start()
thread2.start()
thread3.start()

Output

Number of active threads in the starting: 1
The active threads in the starting is 1 which is the main thread that executes till the program runs
Number of active threads: 4
Value by Thread 3: 3
Number of active threads: 3
Value by Thread 1: 1
Number of active threads: 2
Value by Thread 2: 2

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