print stuff arranged in a table with silly ascii box characters

print_table.py

def center(text, width):
    if len(text) < width:
        diff = width - len(text)
        pad = ' ' * (diff / 2)
        text = pad + text + pad
        if diff % 2:
            text += ' '
    return text

def print_table(fieldnames, table, outstream=None):
    """
    Print a table of data to the given file-like stream (by default, stdout),
    drawing lines between the columns and headers with crude ASCII box
    characters (+, -, |).

    The fieldnames argument should be a list of strings, corresponding to the
    names of the columns in the table.

    The table argument should be represented as a list of rows. Rows should be
    lists of values, and should each have the same length as fieldnames.

    All row values and field names should be bytes (i.e., str, not unicode).

    >>> table = [
    ...    ['monkey', 'banana', 'tree frog'],
    ...    ['giraffe', 'acacia', 'lemur'],
    ...    ['wombat', 'grass', 'mouse']
    ... ]
    >>> headers = ['animal', 'favorite food', 'nemesis']
    >>> print_table(headers, table)
     animal  | favorite food |  nemesis  
    ---------+---------------+-----------
     monkey  | banana        | tree frog 
     giraffe | acacia        | lemur     
     wombat  | grass         | mouse     

    """

    if outstream is None:
        outstream = sys.stdout
    col_widths = [len(f) for f in fieldnames]
    for row in table:
        for colnum, value in enumerate(row):
            col_widths[colnum] = max(col_widths[colnum], len(value))
    outstream.write(' ' + ' | '.join([center(f, w) for (w, f) in zip(col_widths, fieldnames)]) + ' \n')
    outstream.write('+'.join(['-' * (w + 2) for w in col_widths]) + '\n')
    for row in table:
        outstream.write('|'.join([' %-*s ' % (w, v) for (w, v) in zip(col_widths, row)]) + '\n')