Python | os.getpgid() method

OS module in Python provides functions for interacting with the operating system. OS comes under Python’s standard utility modules. This module provides a portable way of using operating system dependent functionality.

All functions in os module raise OSError in the case of invalid or inaccessible file names and paths, or other arguments that have the correct type, but are not accepted by the operating system.

In UNIX-like operating systems, a process group denotes a collection of one or more processes. It is used to control the distribution of a signal that is when a signal is directed to a process group, each member of the process group receives the signal. Every process group is uniquely identified using process group id.
os.getpgid() method in Python is used to get the process group id of the process with specified process id. If the specified process id is 0, process group id of the current process will be returned. Process group id of the current process can be also get using os.getpgrp() method.

Note: os.getpgid() method is only available on UNIX platforms.

Syntax: os.getpgid(pid)

Parameter:
pid: An integer value representing the process id of the process whose process group id is to be found. If pid is 0, it will represent the current process.

Return Type: This method returns an integer value which represents the process group id of the process with specified process id.

Code: Use of os.getpgid() method

# Python program to explain os.getpgid() method

# importing os module
import os

# Get the process group id
# of the current process
# using os.getpgid() method
pid = os.getpid()
pgid = os.getpgid(pid)

# Print the process group id
# of the current process
print("Process group id of the current process:", pgid)

# If pid is 0, process group id
# of the current process
# will be returned
pid = 0
pgid = os.getpgid(pid)
print("Process group id of the current process:", pgid)


# Get the process group id
# of the current process
# using os.getpgrp() method
pgid = os.getpgrp()
print("Process group id of the current process:", pgid)


# Get the process group id
# of the parent process
pid = os.getppid()
pgid = os.getpgid(pid)
print("process group id of the parent process:", pgid)

Output:

Process group id of the current process: 18938
Process group id of the current process: 18938
Process group id of the current process: 18938
process group id of the parent process: 11376