Truncate a string.

    Parameters
    ----------
    string : `str`
        String to truncate.
    maxlen : `int`
        Maximum string length.
    end : `boolean`, optional
        Remove characters from the end (default: `True`).

    Raises
    ------
    ValueError
        If `maxlen` <= 3.

    Returns
    -------
    `str`
        Truncated string.

    Examples
    --------
    >>> truncate('str', 6)
    'str'
    >>> truncate('long string', 8)
    'long ...'
    >>> truncate('long string', 8, False)
    '...tring'

def truncate(string, maxlen, end=True):
    """Truncate a string.

    Parameters
    ----------
    string : `str`
        String to truncate.
    maxlen : `int`
        Maximum string length.
    end : `boolean`, optional
        Remove characters from the end (default: `True`).

    Raises
    ------
    ValueError
        If `maxlen` <= 3.

    Returns
    -------
    `str`
        Truncated string.

    Examples
    --------
    >>> truncate('str', 6)
    'str'
    >>> truncate('long string', 8)
    'long ...'
    >>> truncate('long string', 8, False)
    '...tring'
    """
    if maxlen <= 3:
        raise ValueError('maxlen <= 3')

    if len(string) <= maxlen:
        return string

    if end:
        return string[:maxlen - 3] + '...'

    return '...' + string[3 - maxlen:]