human
pid determine existence.
assistant
Here is a Python code to determine existence

import os

def pid_exists(pid):
    """
    Return True if the pid exists, False otherwise.
    """
    return os.path.exists(pid)

# Enter the pid
pid = "/home/rosey/Desktop/test.pid"

# Calling the function
print((pid_exists(pid)))

#Example Output
# True

#Remember to inspect code for bugs.