Regex split test cases (feel free to add more)

main.py

import re

lst = [
    (
        r"(x)",
        "1x2",
        ["1", "x", "2"],
    ),
    (
        r"([^\d]+)",
        "1-2",
        ["1", "-", "2"],
    ),
    (
        r"(\s+)",
        "this  is a \n\ntest",
        ["this", "  ", "is", " ", "a", " \n\n", "test"],
    ),
    (
        r"([^0-9a-zA-Z_])",
        " C# is great! (not actually) :)",
        ["", " ", "C", "#", "", " ", "is", " ", "great", "!", "", " ", "", "(", "not", " ", "actually", ")", "", " ", "", ":", "", ")", ""],
    ),
    (
        r"([a-zA-Z](?:[a-zA-Z']*[a-zA-Z])?)",
        'He said, "I\'d like to eat cake!"',
        ["", "He", " ", "said", ', "', "I'd", " ", "like", " ", "to", " ", "eat", " ", "cake", '!"'],
    ),
]


def main():
    for pattern, in_text, expected_out in lst:
        out = re.split(pattern, in_text)
        assert out == expected_out, (f'Regex: {pattern}, Text: {in_text}, \nOut: {out} '
                                     f'\nExpected out: {expected_out}')


if __name__ == '__main__':
    main()