In a Python script, the os.access module can be used to determine if a file or a directory is readable and writable.

#!/usr/bin/python3
import getpass
import os

whoami = getpass.getuser()

object = "/usr/local/foo"

if os.access(object, os.R_OK):
  print(f"{object} is readable by {whoami}")
else:
  print(f"{object} is NOT readable by {whoami}")

if os.access(object, os.W_OK):
  print(f"{object} is writeable by {whoami}")
else:
  print(f"{object} is NOT writeable by {whoami}")

You will typically want to also first use os.path.exists to determine if the path exists and os.path.isfile or os.path.isdir to determine if the object is a file or is a directory.

#!/usr/bin/python3
import getpass
import os

whoami = getpass.getuser()

object = "/usr/local/foo"

if os.path.exists(object):
  print(f"{object} exists"
else:
  print(f"{object} does NOT exists"

if os.path.isfile(object):
  print(f"{object} is a file"
else:
  print(f"{object} is NOT a file"

if os.access(object, os.R_OK):
  print(f"{object} is readable by {whoami}"
else:
  print(f"{object} is NOT readable by {whoami}"

if os.access(object, os.W_OK):
  print(f"{object} is writeable by {whoami}"
else:
  print(f"{object} is NOT writeable by {whoami}"