What is a process identifier (PID)?

Process ID (PID) is a unique positive integer assigned by the operating system to each running process for identification.

In Python, you can get the current process's PID as follows:

import os

pid = os.getpid()
# pid will contain the current process's identifier

Information about the PID is used by the operating system and other processes for managing and interacting with a specific process. This includes, for example:

• Terminating the process.
• Sending signals to the process.
• Monitoring resource usage by the process.

The PID is unique within the current session of the operating system but may be reused after the process terminates.