os.path

os.path.dirname
os.path.basename
os.path.realpath
os.path.isfile

if not os.path.isfile(file1) or not os.path.isfile(file2):
   raise FileNotFoundError("One or both files are missing.")

Related

• Pathlib

See also

• import os, os.path
• import, import (Python): import [ os | argparse | sys | psutil | yaml ], from
• Python, PIP, GIL, Flask, Django, Marshmallow, def, logging, Pandas, Numpy, AWS Chalice, import, from, tuple, list, Python exceptions, virtualenv, .append, pytz, TZ, print, python3 -c, os, PEP, Python Institute, Methods: Dunder methods, Flake8, Python collections, Function decorators in Python, Click python library, Python module, Flower, kwargs, Black (Python), Python list structure, Mypy, variables, Casting, try:, pydoc, argparse, Anaconda, pyenv, setup.py, python3 --version, python3 --help, Data Classes, raise