Simple python program example to run tests together with your code using pytest.

main.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import os
import sys
import timeit
import datetime
import argparse
import pathlib

from pathlib import Path
from typing import Optional

try:
    import pytest
except:
    print('Disabling tests as pytest is not installed.')
    class Struct(object): pass
    pytest = Struct()
    pytest.mark = Struct()
    pytest.mark.parametrize = lambda x, y: lambda z: None


g_start_time = timeit.default_timer()
SCRIPT_DIRECTORY = pathlib.Path(__file__).parent.resolve()


# Call it without the start parameter to print the time since the last call
def print_time(start=None):
    global g_start_time
    start = g_start_time if start is None else start
    end = timeit.default_timer()
    print("Time elapsed %s... " % datetime.timedelta(seconds=end-start), end="\n", file=sys.stderr)
    g_start_time = end


def run_algorithm(somepath, someparameter, someotherparameter):
    print_time()
    return [someparameter + someotherparameter]


# Use a "struct" to not keep using global keyword everywhere
class Struct(object): pass
s = Struct()
s.somesetting = 'some'
s.someothersetting = 'other'

@pytest.mark.parametrize('tests', [
    (SCRIPT_DIRECTORY / 'some.txt', [
        'someother',
    ]),
    (SCRIPT_DIRECTORY / 'someother.txt', [
        'someother',
    ]),
])
def test_name(tests):
    file_path, expected = tests
    results = run_algorithm(file_path, s.somesetting, s.someothersetting)
    assert results == expected


def main() -> Optional[int]:
    argumentsNamespace = g_argumentParser.parse_args()
    if argumentsNamespace.help:
        g_argumentParser.print_help()
        return

    run_tests = argumentsNamespace.run_tests
    if isinstance(run_tests, list):
        args = [sys.argv[0], '-vv', '-rP']
        if run_tests:
            args.extend(run_tests)
        print('Running tests %s' % args)
        return pytest.main(args)

    directory = argumentsNamespace.directory
    if directory:
        for file_path in sorted(Path(directory).resolve().glob('*.txt')):
            run_algorithm(file_path, 'some', 'other')
        return


g_argumentParser = argparse.ArgumentParser(
        description = \
"""
Single test and main file example.

Run your code and your tests with a single file.
""",
        formatter_class=argparse.RawTextHelpFormatter,
        add_help=False,
    )

# https://stackoverflow.com/questions/35847084/customize-argparse-help-message
g_argumentParser.add_argument( "-h", "--help", action="store_true",
help= """
Show this help message and exits.
""" )

g_argumentParser.add_argument( "-t", "--run-tests", action="store", nargs=argparse.REMAINDER, default=None,
        help=
"""
Run unit tests and exit (used only by developers). To run all tests: python3 main.py -t
To run a single test:
1. python3 main.py -t -s -k test_name
2. python3 main.py -t -s -k test_name[testes0]
""" )

g_argumentParser.add_argument( "-d", "--directory", action="store", default=None,
        help=
"""
Run the algorithm for all files in a directory.
""" )


if __name__ == '__main__':
    start = timeit.default_timer()
    code = main()
    print_time(start)
    sys.exit(code if code else 0)