Multiprocessing

Use the built-in multiprocessing module.

import multiprocessing

Quick links:

Creating and Running Processes

The core class is multiprocessing.Process.

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

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

Create a Process object:
```
process = multiprocessing.Process(target=my_process_task, args=(value1, value2))
```
- target: The function to be executed in the new process.
- 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 process:
```
process.start()
```
- This starts the process and executes the target function.
Wait for the process to complete:
```
process.join()
```
- This blocks the calling program until the process whose join() method is called terminates.

Basic Example

import multiprocessing
import time

def worker_function(name):
    print(f"Worker process {name} starting...")
    time.sleep(2) # Simulate doing some CPU-bound work
    print(f"Worker process {name} finishing.")

if __name__ == "__main__":
    # Create two processes
    p1 = multiprocessing.Process(target=worker_function, args=("Alpha",))
    p2 = multiprocessing.Process(target=worker_function, args=("Beta",))

    # Start the processes
    p1.start()
    p2.start()

    # Wait for both processes to complete
    p1.join()
    p2.join()

    print("All processes finished.")

Important: The if __name__ == "__main__": block is crucial on some operating systems (like Windows) to prevent processes from recursively spawning new processes when the module is imported by the new process.