The new_directory function creates a new directory inside the current working directory, then creates a new empty file inside the new directory, and returns the list of files in that directory.

new_directory.py

import os

def new_directory(directory, filename):
  # Before creating a new directory, check to see if it already exists
  if os.path.isdir(directory) == False:
    os.mkdir(directory)

  # Create the new file inside of the new directory
  os.chdir(directory)
  if os.path.isfile(filename) == False:
    os.mknod(filename)
  os.chdir('..')

  # Return the list of files in the new directory
  return os.listdir(directory)

print(new_directory("PythonPrograms", "script.py"))