Indent lines of text in a string

indent_lines.py

def indent_lines(text: str, spaces: int | str = 4) -> str:
    r"""Indent lines of text by some fixed amount.

    :param text: The text to indent.
    :param spaces: The amount of spaces to indent by, or an arbitrary string to use as a
        line prefix.
    :returns: The indented text.
    """
    if isinstance(spaces, int):
        spaces = " " * spaces
    return "".join([spaces + line for line in text.splitlines(True)])