Python - Naming the Threads

In Python, naming a thread involves assigning a string as an identifier to the thread object. Thread names in Python are primarily used for identification purposes only and do not affect the thread's behavior or semantics. Multiple threads can share the same name, and names can be specified during the thread's initialization or changed dynamically.

Thread naming in Python provides a straightforward way to identify and manage threads within a concurrent program. By assigning meaningful names, users can enhance code clarity and easily debug the complex multi-threaded applications.

Naming the Threads in Python

When you create a thread using threading.Thread() class, you can specify its name using the name parameter. If not provided, Python assigns a default name like the following pattern "Thread-N", where N is a small decimal number. Alternatively, if you specify a target function, the default name format becomes "Thread-N (target_function_name)".

Example

Here is an example demonstrates assigning custom and default names to threads created using threading.Thread() class, and displays how names can reflect target functions.

from threading import Thread
import threading
from time import sleep

def my_function_1(arg):
   print("This tread name is", threading.current_thread().name)

# Create thread objects
thread1 = Thread(target=my_function_1, name='My_thread', args=(2,))
thread2 = Thread(target=my_function_1, args=(3,))

print("This tread name is", threading.current_thread().name)

# Start the first thread and wait for 0.2 seconds
thread1.start()
thread1.join()

# Start the second thread and wait for it to complete
thread2.start()
thread2.join()

On executing the above, it will produce the following results −

This tread name is MainThread
This tread name is My_thread
This tread name is Thread-1 (my_function_1)

Dynamically Assigning Names to the Python Threads

You can assign or change a thread's name dynamically by directly modifying the name attribute of the thread object.

Example

This example shows how to dynamically change thread names by modifying the name attribute of the thread object.

from threading import Thread
import threading
from time import sleep

def my_function_1(arg):
   threading.current_thread().name = "custom_name"
   print("This tread name is", threading.current_thread().name)

# Create thread objects
thread1 = Thread(target=my_function_1, name='My_thread', args=(2,))
thread2 = Thread(target=my_function_1, args=(3,))

print("This tread name is", threading.current_thread().name)

# Start the first thread and wait for 0.2 seconds
thread1.start()
thread1.join()

# Start the second thread and wait for it to complete
thread2.start()
thread2.join()

When you execute the above code, it will produce the following results −

This tread name is MainThread
This tread name is custom_name
This tread name is custom_name

Example

Threads can be initialized with custom names and even renamed after creation. This example demonstrates creating threads with custom names and modifying a thread's name after creation.

import threading

def addition_of_numbers(x, y):
   print("This Thread name is :", threading.current_thread().name)
   result = x + y

def cube_number(i):
   result = i ** 3
   print("This Thread name is :", threading.current_thread().name)

def basic_function():
   print("This Thread name is :", threading.current_thread().name)

# Create threads with custom names
t1 = threading.Thread(target=addition_of_numbers, name='My_thread', args=(2, 4))
t2 = threading.Thread(target=cube_number, args=(4,))
t3 = threading.Thread(target=basic_function)

# Start and join threads
t1.start()
t1.join()

t2.start()
t2.join()

t3.name = 'custom_name'  # Assigning name after thread creation
t3.start()
t3.join()

print(threading.current_thread().name)  # Print main thread's name

Upon execution, the above code will produce the following results −

This Thread name is : My_thread
This Thread name is : Thread-1 (cube_number)
This Thread name is : custom_name
MainThread