Multi-threading

Use the built-in threading module.

import threading

Quick links:

Creating and Running Threads

The core class is threading.Thread.

Define the target function: This is the code that the new thread will run.

def my_thread_task(argument1, argument2):
    # Code to be executed in the new thread
    print(f"Thread received: {argument1}, {argument2}")
    # ... perform task ...

Create a Thread object:
```
thread = threading.Thread(target=my_thread_task, args=(value1, value2))
```
- target: The function to be executed in the new thread.
- args: A tuple of positional arguments to pass to the target function. Use a comma after the single item if passing only one argument (e.g., args=(value1,)).
- kwargs: (Optional) A dictionary of keyword arguments to pass to the target function.
Start the thread:
```
thread.start()
```
- This starts the thread and executes the target function.
Wait for the thread to complete:
```
thread.join()
```
- This blocks the calling program until the thread whose join() method is called terminates.

Basic Example

import threading
import time

def worker_function(name):
    print(f"Worker thread {name} starting...")
    time.sleep(2) # Simulate doing some I/O work
    print(f"Worker thread {name} finishing.")

# Create two threads
t1 = threading.Thread(target=worker_function, args=("Alpha",))
t2 = threading.Thread(target=worker_function, args=("Beta",))

# Start the threads
t1.start()
t2.start()

# Wait for both threads to complete
t1.join()
t2.join()

print("All threads finished.")

Sharing Data & The GIL

Threads share memory, which makes data sharing easier but requires careful synchronization (using Locks, Semaphores, etc.) to prevent race conditions.