Python: Show the individual process IDs involved

Last update on April 17 2025 13:00:56 (UTC/GMT +8 hours)

Multiprocessing Process IDs

In multiprocessing, processes are spawned by creating a Process object.
Write a Python program to show the individual process IDs (parent process, process ID etc.) involved.

Sample Solution:

Python Code:

# Import the 'Process' class from the 'multiprocessing' module.
from multiprocessing import Process

# Import the 'os' module for interacting with the operating system.
import os

# Define a function 'info' to print process-related information.
def info(title):
    print(title)
    print('module name:', __name__)
    print('parent process:', os.getppid())
    print('process id:', os.getpid())

# Define a function 'f' that takes a name as an argument.
def f(name):
    # Call the 'info' function to print process-related information.
    info('function f')
    # Print a greeting using the provided name.
    print('hello', name)

# Check if the script is being run as the main program.
if __name__ == '__main__':
    # Call the 'info' function to print process-related information for the main process.
    info('Main line')

    # Create a new 'Process' object, specifying the target function 'f' and its arguments.
    p = Process(target=f, args=('bob',))

    # Start the new process.
    p.start()

    # Wait for the child process to complete before continuing.
    p.join()

Sample Output:

Main line
module name: __main__
parent process: 23967
process id: 27986
function f
module name: __main__
parent process: 27986
process id: 27987
hello bob

Explanation:

Here is a breakdown of the above Python code:

Module Imports:

The code imports the 'Process' class from the 'multiprocessing' module for working with processes.
The 'os' module is imported for interacting with the operating system.

Function definitions:

The 'info' function prints information about the module name, parent process ID, and process ID.
The 'f' function prints a greeting using the provided name.

Main Program:

The script checks if it is being run as the main program using if name == '__main__':.

Process creation and execution:

A new 'Process' object is created, specifying the target function 'f' and its arguments.
The child process is started using p.start().
The script waits for the child process to complete before continuing using p.join().

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to create multiple processes using the multiprocessing module and print their process IDs.
Write a Python program to spawn child processes and display both parent and child process IDs using os.getpid().
Write a Python program to demonstrate process creation and ID retrieval by launching several processes concurrently.
Write a Python program to print the process IDs of the main process and its spawned child processes using the multiprocessing library.

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Python Code Editor:

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