def count_line(file=None):
    """
    Count lines in an input file.

    Parameters
    ----------
    file : str
        Absolute or full path of input file.

    Returns
    -------
    i + 1 : int
        Number of line in file.

    Examples
    --------
    >>> file = "/home/Jack/[Fe(1-bpp)2][BF4]2-HS.xyz"
    >>> count_line(file)
    27

    """
    if file is None:
        raise TypeError('count_line needs one argument: input file')
    with open(file) as f:
        for i, l in enumerate(f):
            pass
    return i + 1
