Python Threading Module
The threading module constructs higher-level threading interfaces on top of the lower level _thread module. It allows you to run multiple threads (tasks, function calls) at the same time.
Importing the Module
import threadingCreating and Starting Threads
To create a thread, you create an instance of the Thread class and pass it the function you want to run via the target argument.
import threading
import time
def print_numbers():
for i in range(5):
time.sleep(1)
print(f"Number: {i}")
def print_letters():
for letter in 'abcde':
time.sleep(1)
print(f"Letter: {letter}")
# Create threads
t1 = threading.Thread(target=print_numbers)
t2 = threading.Thread(target=print_letters)
# Start threads
t1.start()
t2.start()
# Wait for threads to complete
t1.join()
t2.join()
print("Done!")Thread Synchronization (Locks)
When multiple threads access shared resources, race conditions can occur. The Lock class solves this.
import threading
x = 0
lock = threading.Lock()
def increment():
global x
for _ in range(100000):
with lock:
x += 1
t1 = threading.Thread(target=increment)
t2 = threading.Thread(target=increment)
t1.start()
t2.start()
t1.join()
t2.join()
print(f"Final value of x: {x}")Daemon Threads
A daemon thread runs in the background and does not prevent the program from exiting.
# t = threading.Thread(target=background_task, daemon=True)
# t.start()