def display_enumerated_lines(filename):
    """Display lines of files with line number as prefix
    use `enumerate` function"""


def reverse_lines_y(filename):
    """Reads data from `<filename>` and writes reversed lines to file `<filename>_reversed_y'
    e.g.
    a b  >  b a
    c d  >  d c
    """


def reverse_lines_x(filename):
    """Reads data from `<filename>` and writes reversed lines to file `<filename>_reversed_x'
    e.g.
    a b  >  c d
    c d  >  a b
    """


def reverse_lines(filename):
    """Reads data from `<filename>` and writes reversed lines to file `<filename>_reversed'
    e.g.
    a b  >  d c
    c d  >  b a
    """


if __name__ == '__main__':
    filename = './data/matrix'

    display_enumerated_lines(filename)
    reverse_lines_x(filename)
    reverse_lines_y(filename)
    reverse_lines(filename)
