CLI helpers

table.py

def table(rows, add_index=False):
    """
    Generates a table from a list of lists. The first row should contain the
    headers.
    """
    rows = [list(row) for row in rows]
    headers = rows[0]
    body = rows[1:]
    if add_index:
        headers.insert(0, '#')
        body = [[i] + row for i, row in enumerate(body)]

    # Determining the length of the columns
    col_lens = []
    for i in range(len(body[0])):
        col_lens.append(len(str(max([x[i] for x in body] + headers[i:i+1],
                            key=lambda x: len(str(x))))))

    formats = []
    hformats = []
    for i in range(len(body[0])):
        col_len = col_lens[i]
        if isinstance(rows[0][i], int):
            # align right
            formats.append('{{:>{}}}'.format(col_len))
        else:
            # align left
            formats.append('{{:{}}}'.format(col_len))
        hformats.append('{{:{}}}'.format(col_len))
    pattern = ' | '.join(formats)
    hpattern = ' | '.join(hformats)
    separator = '-+-'.join('-' * n for n in col_lens)
    output = []
    output.append(hpattern.format(*headers))
    output.append(separator)
    for row in body:
        output.append(pattern.format(*row))
    return '\n'.join(output)