256colors_convert

#!/usr/bin/env python
# From https://gist.github.com/MicahElliott/719710
"""Convert values between RGB hex codes and xterm-256 color codes.

Nice long listing of all 256 colors and their codes. Useful for
developing console color themes, or even script output schemes.

Resources:
* http://en.wikipedia.org/wiki/8-bit_color
* http://en.wikipedia.org/wiki/ANSI_escape_code
* /usr/share/X11/rgb.txt

I'm not sure where this script was inspired from. I think I must have
written it from scratch, though it's been several years now.
"""

__author__    = 'Micah Elliott http://MicahElliott.com'
__version__   = '0.1'
__copyright__ = 'Copyright (C) 2011 Micah Elliott.  All rights reserved.'
__license__   = 'WTFPL http://sam.zoy.org/wtfpl/'

#---------------------------------------------------------------------

import sys, re

CLUT = [  # color look-up table
#    8-bit, RGB hex

    # Primary 3-bit (8 colors). Unique representation!
    ('00',  '000000'),
    ('01',  '800000'),
    ('02',  '008000'),
    ('03',  '808000'),
    ('04',  '000080'),
    ('05',  '800080'),
    ('06',  '008080'),
    ('07',  'c0c0c0'),

    # Equivalent "bright" versions of original 8 colors.
    ('08',  '808080'),
    ('09',  'ff0000'),
    ('10',  '00ff00'),
    ('11',  'ffff00'),
    ('12',  '0000ff'),
    ('13',  'ff00ff'),
    ('14',  '00ffff'),
    ('15',  'ffffff'),

    # Strictly ascending.
    ('16',  '000000'),
    ('17',  '00005f'),
    ('18',  '000087'),
    ('19',  '0000af'),
    ('20',  '0000d7'),
    ('21',  '0000ff'),
    ('22',  '005f00'),
    ('23',  '005f5f'),
    ('24',  '005f87'),
    ('25',  '005faf'),
    ('26',  '005fd7'),
    ('27',  '005fff'),
    ('28',  '008700'),
    ('29',  '00875f'),
    ('30',  '008787'),
    ('31',  '0087af'),
    ('32',  '0087d7'),
    ('33',  '0087ff'),
    ('34',  '00af00'),
    ('35',  '00af5f'),
    ('36',  '00af87'),
    ('37',  '00afaf'),
    ('38',  '00afd7'),
    ('39',  '00afff'),
    ('40',  '00d700'),
    ('41',  '00d75f'),
    ('42',  '00d787'),
    ('43',  '00d7af'),
    ('44',  '00d7d7'),
    ('45',  '00d7ff'),
    ('46',  '00ff00'),
    ('47',  '00ff5f'),
    ('48',  '00ff87'),
    ('49',  '00ffaf'),
    ('50',  '00ffd7'),
    ('51',  '00ffff'),
    ('52',  '5f0000'),
    ('53',  '5f005f'),
    ('54',  '5f0087'),
    ('55',  '5f00af'),
    ('56',  '5f00d7'),
    ('57',  '5f00ff'),
    ('58',  '5f5f00'),
    ('59',  '5f5f5f'),
    ('60',  '5f5f87'),
    ('61',  '5f5faf'),
    ('62',  '5f5fd7'),
    ('63',  '5f5fff'),
    ('64',  '5f8700'),
    ('65',  '5f875f'),
    ('66',  '5f8787'),
    ('67',  '5f87af'),
    ('68',  '5f87d7'),
    ('69',  '5f87ff'),
    ('70',  '5faf00'),
    ('71',  '5faf5f'),
    ('72',  '5faf87'),
    ('73',  '5fafaf'),
    ('74',  '5fafd7'),
    ('75',  '5fafff'),
    ('76',  '5fd700'),
    ('77',  '5fd75f'),
    ('78',  '5fd787'),
    ('79',  '5fd7af'),
    ('80',  '5fd7d7'),
    ('81',  '5fd7ff'),
    ('82',  '5fff00'),
    ('83',  '5fff5f'),
    ('84',  '5fff87'),
    ('85',  '5fffaf'),
    ('86',  '5fffd7'),
    ('87',  '5fffff'),
    ('88',  '870000'),
    ('89',  '87005f'),
    ('90',  '870087'),
    ('91',  '8700af'),
    ('92',  '8700d7'),
    ('93',  '8700ff'),
    ('94',  '875f00'),
    ('95',  '875f5f'),
    ('96',  '875f87'),
    ('97',  '875faf'),
    ('98',  '875fd7'),
    ('99',  '875fff'),
    ('100', '878700'),
    ('101', '87875f'),
    ('102', '878787'),
    ('103', '8787af'),
    ('104', '8787d7'),
    ('105', '8787ff'),
    ('106', '87af00'),
    ('107', '87af5f'),
    ('108', '87af87'),
    ('109', '87afaf'),
    ('110', '87afd7'),
    ('111', '87afff'),
    ('112', '87d700'),
    ('113', '87d75f'),
    ('114', '87d787'),
    ('115', '87d7af'),
    ('116', '87d7d7'),
    ('117', '87d7ff'),
    ('118', '87ff00'),
    ('119', '87ff5f'),
    ('120', '87ff87'),
    ('121', '87ffaf'),
    ('122', '87ffd7'),
    ('123', '87ffff'),
    ('124', 'af0000'),
    ('125', 'af005f'),
    ('126', 'af0087'),
    ('127', 'af00af'),
    ('128', 'af00d7'),
    ('129', 'af00ff'),
    ('130', 'af5f00'),
    ('131', 'af5f5f'),
    ('132', 'af5f87'),
    ('133', 'af5faf'),
    ('134', 'af5fd7'),
    ('135', 'af5fff'),
    ('136', 'af8700'),
    ('137', 'af875f'),
    ('138', 'af8787'),
    ('139', 'af87af'),
    ('140', 'af87d7'),
    ('141', 'af87ff'),
    ('142', 'afaf00'),
    ('143', 'afaf5f'),
    ('144', 'afaf87'),
    ('145', 'afafaf'),
    ('146', 'afafd7'),
    ('147', 'afafff'),
    ('148', 'afd700'),
    ('149', 'afd75f'),
    ('150', 'afd787'),
    ('151', 'afd7af'),
    ('152', 'afd7d7'),
    ('153', 'afd7ff'),
    ('154', 'afff00'),
    ('155', 'afff5f'),
    ('156', 'afff87'),
    ('157', 'afffaf'),
    ('158', 'afffd7'),
    ('159', 'afffff'),
    ('160', 'd70000'),
    ('161', 'd7005f'),
    ('162', 'd70087'),
    ('163', 'd700af'),
    ('164', 'd700d7'),
    ('165', 'd700ff'),
    ('166', 'd75f00'),
    ('167', 'd75f5f'),
    ('168', 'd75f87'),
    ('169', 'd75faf'),
    ('170', 'd75fd7'),
    ('171', 'd75fff'),
    ('172', 'd78700'),
    ('173', 'd7875f'),
    ('174', 'd78787'),
    ('175', 'd787af'),
    ('176', 'd787d7'),
    ('177', 'd787ff'),
    ('178', 'd7af00'),
    ('179', 'd7af5f'),
    ('180', 'd7af87'),
    ('181', 'd7afaf'),
    ('182', 'd7afd7'),
    ('183', 'd7afff'),
    ('184', 'd7d700'),
    ('185', 'd7d75f'),
    ('186', 'd7d787'),
    ('187', 'd7d7af'),
    ('188', 'd7d7d7'),
    ('189', 'd7d7ff'),
    ('190', 'd7ff00'),
    ('191', 'd7ff5f'),
    ('192', 'd7ff87'),
    ('193', 'd7ffaf'),
    ('194', 'd7ffd7'),
    ('195', 'd7ffff'),
    ('196', 'ff0000'),
    ('197', 'ff005f'),
    ('198', 'ff0087'),
    ('199', 'ff00af'),
    ('200', 'ff00d7'),
    ('201', 'ff00ff'),
    ('202', 'ff5f00'),
    ('203', 'ff5f5f'),
    ('204', 'ff5f87'),
    ('205', 'ff5faf'),
    ('206', 'ff5fd7'),
    ('207', 'ff5fff'),
    ('208', 'ff8700'),
    ('209', 'ff875f'),
    ('210', 'ff8787'),
    ('211', 'ff87af'),
    ('212', 'ff87d7'),
    ('213', 'ff87ff'),
    ('214', 'ffaf00'),
    ('215', 'ffaf5f'),
    ('216', 'ffaf87'),
    ('217', 'ffafaf'),
    ('218', 'ffafd7'),
    ('219', 'ffafff'),
    ('220', 'ffd700'),
    ('221', 'ffd75f'),
    ('222', 'ffd787'),
    ('223', 'ffd7af'),
    ('224', 'ffd7d7'),
    ('225', 'ffd7ff'),
    ('226', 'ffff00'),
    ('227', 'ffff5f'),
    ('228', 'ffff87'),
    ('229', 'ffffaf'),
    ('230', 'ffffd7'),
    ('231', 'ffffff'),

    # Gray-scale range.
    ('232', '080808'),
    ('233', '121212'),
    ('234', '1c1c1c'),
    ('235', '262626'),
    ('236', '303030'),
    ('237', '3a3a3a'),
    ('238', '444444'),
    ('239', '4e4e4e'),
    ('240', '585858'),
    ('241', '626262'),
    ('242', '6c6c6c'),
    ('243', '767676'),
    ('244', '808080'),
    ('245', '8a8a8a'),
    ('246', '949494'),
    ('247', '9e9e9e'),
    ('248', 'a8a8a8'),
    ('249', 'b2b2b2'),
    ('250', 'bcbcbc'),
    ('251', 'c6c6c6'),
    ('252', 'd0d0d0'),
    ('253', 'dadada'),
    ('254', 'e4e4e4'),
    ('255', 'eeeeee'),
]

NAME_TO_HEX = {
    'aliceblue': 'f0f8ff',
    'antiquewhite': 'faebd7',
    'aqua': '00ffff',
    'aquamarine': '7fffd4',
    'azure': 'f0ffff',
    'beige': 'f5f5dc',
    'bisque': 'ffe4c4',
    'black': '000000',
    'blanchedalmond': 'ffebcd',
    'blue': '0000ff',
    'blueviolet': '8a2be2',
    'brown': 'a52a2a',
    'burlywood': 'deb887',
    'cadetblue': '5f9ea0',
    'chartreuse': '7fff00',
    'chocolate': 'd2691e',
    'coral': 'ff7f50',
    'cornflowerblue': '6495ed',
    'cornsilk': 'fff8dc',
    'crimson': 'dc143c',
    'cyan': '00ffff',
    'darkblue': '00008b',
    'darkcyan': '008b8b',
    'darkgoldenrod': 'b8860b',
    'darkgray': 'a9a9a9',
    'darkgrey': 'a9a9a9',
    'darkgreen': '006400',
    'darkkhaki': 'bdb76b',
    'darkmagenta': '8b008b',
    'darkolivegreen': '556b2f',
    'darkorange': 'ff8c00',
    'darkorchid': '9932cc',
    'darkred': '8b0000',
    'darksalmon': 'e9967a',
    'darkseagreen': '8fbc8f',
    'darkslateblue': '483d8b',
    'darkslategray': '2f4f4f',
    'darkslategrey': '2f4f4f',
    'darkturquoise': '00ced1',
    'darkviolet': '9400d3',
    'deeppink': 'ff1493',
    'deepskyblue': '00bfff',
    'dimgray': '696969',
    'dimgrey': '696969',
    'dodgerblue': '1e90ff',
    'firebrick': 'b22222',
    'floralwhite': 'fffaf0',
    'forestgreen': '228b22',
    'fuchsia': 'ff00ff',
    'gainsboro': 'dcdcdc',
    'ghostwhite': 'f8f8ff',
    'gold': 'ffd700',
    'goldenrod': 'daa520',
    'gray': '808080',
    'grey': '808080',
    'green': '008000',
    'greenyellow': 'adff2f',
    'honeydew': 'f0fff0',
    'hotpink': 'ff69b4',
    'indianred': 'cd5c5c',
    'indigo': '4b0082',
    'ivory': 'fffff0',
    'khaki': 'f0e68c',
    'lavender': 'e6e6fa',
    'lavenderblush': 'fff0f5',
    'lawngreen': '7cfc00',
    'lemonchiffon': 'fffacd',
    'lightblue': 'add8e6',
    'lightcoral': 'f08080',
    'lightcyan': 'e0ffff',
    'lightgoldenrodyellow': 'fafad2',
    'lightgray': 'd3d3d3',
    'lightgrey': 'd3d3d3',
    'lightgreen': '90ee90',
    'lightpink': 'ffb6c1',
    'lightsalmon': 'ffa07a',
    'lightseagreen': '20b2aa',
    'lightskyblue': '87cefa',
    'lightslategray': '778899',
    'lightslategrey': '778899',
    'lightsteelblue': 'b0c4de',
    'lightyellow': 'ffffe0',
    'lime': '00ff00',
    'limegreen': '32cd32',
    'linen': 'faf0e6',
    'magenta': 'ff00ff',
    'maroon': '800000',
    'mediumaquamarine': '66cdaa',
    'mediumblue': '0000cd',
    'mediumorchid': 'ba55d3',
    'mediumpurple': '9370d8',
    'mediumseagreen': '3cb371',
    'mediumslateblue': '7b68ee',
    'mediumspringgreen': '00fa9a',
    'mediumturquoise': '48d1cc',
    'mediumvioletred': 'c71585',
    'midnightblue': '191970',
    'mintcream': 'f5fffa',
    'mistyrose': 'ffe4e1',
    'moccasin': 'ffe4b5',
    'navajowhite': 'ffdead',
    'navy': '000080',
    'oldlace': 'fdf5e6',
    'olive': '808000',
    'olivedrab': '6b8e23',
    'orange': 'ffa500',
    'orangered': 'ff4500',
    'orchid': 'da70d6',
    'palegoldenrod': 'eee8aa',
    'palegreen': '98fb98',
    'paleturquoise': 'afeeee',
    'palevioletred': 'd87093',
    'papayawhip': 'ffefd5',
    'peachpuff': 'ffdab9',
    'peru': 'cd853f',
    'pink': 'ffc0cb',
    'plum': 'dda0dd',
    'powderblue': 'b0e0e6',
    'purple': '800080',
    'red': 'ff0000',
    'rosybrown': 'bc8f8f',
    'royalblue': '4169e1',
    'saddlebrown': '8b4513',
    'salmon': 'fa8072',
    'sandybrown': 'f4a460',
    'seagreen': '2e8b57',
    'seashell': 'fff5ee',
    'sienna': 'a0522d',
    'silver': 'c0c0c0',
    'skyblue': '87ceeb',
    'slateblue': '6a5acd',
    'slategray': '708090',
    'slategrey': '708090',
    'snow': 'fffafa',
    'springgreen': '00ff7f',
    'steelblue': '4682b4',
    'tan': 'd2b48c',
    'teal': '008080',
    'thistle': 'd8bfd8',
    'tomato': 'ff6347',
    'turquoise': '40e0d0',
    'violet': 'ee82ee',
    'wheat': 'f5deb3',
    'white': 'ffffff',
    'whitesmoke': 'f5f5f5',
    'yellow': 'ffff00',
    'yellowgreen': '9acd32',
}

def _str2hex(hexstr):
    return int(hexstr, 16)

def _strip_hash(rgb):
    # Strip leading `#` if exists.
    if rgb.startswith('#'):
        rgb = rgb.lstrip('#')
    return rgb

def _create_dicts():
    short2rgb_dict = dict(CLUT)
    rgb2short_dict = {}
    for k, v in short2rgb_dict.items():
        rgb2short_dict[v] = k
    return rgb2short_dict, short2rgb_dict

def short2rgb(short):
    return SHORT2RGB_DICT[short]

def print_all():
    """ Print all 256 xterm color codes.
    """
    for short, rgb in CLUT:
        sys.stdout.write('\033[48;5;%sm%s:%s' % (short, short, rgb))
        sys.stdout.write("\033[0m  ")
        sys.stdout.write('\033[38;5;%sm%s:%s' % (short, short, rgb))
        sys.stdout.write("\033[0m\n")
    print "Printed all codes."
    print "You can translate a hex or 0-255 code by providing an argument."

def rgb2short(rgb):
    """ Find the closest xterm-256 approximation to the given RGB value.
    @param rgb: Hex code representing an RGB value, eg, 'abcdef'
    @returns: String between 0 and 255, compatible with xterm.
    >>> rgb2short('123456')
    ('23', '005f5f')
    >>> rgb2short('ffffff')
    ('231', 'ffffff')
    >>> rgb2short('0DADD6') # vimeo logo
    ('38', '00afd7')
    """
    rgb = _strip_hash(rgb)
    incs = (0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff)
    # Break 6-char RGB code into 3 integer vals.
    parts = [ int(h, 16) for h in re.split(r'(..)(..)(..)', rgb)[1:4] ]
    res = []
    for part in parts:
        i = 0
        while i < len(incs)-1:
            s, b = incs[i], incs[i+1]  # smaller, bigger
            if s <= part <= b:
                s1 = abs(s - part)
                b1 = abs(b - part)
                if s1 < b1: closest = s
                else: closest = b
                res.append(closest)
                break
            i += 1
    #print '***', res
    res = ''.join([ ('%02.x' % i) for i in res ])
    equiv = RGB2SHORT_DICT[ res ]
    #print '***', res, equiv
    return equiv, res

RGB2SHORT_DICT, SHORT2RGB_DICT = _create_dicts()

#---------------------------------------------------------------------

if __name__ == '__main__':
    import doctest
    doctest.testmod()
    if len(sys.argv) == 1:
        print_all()
        raise SystemExit
    arg = sys.argv[1]
    if re.match(r'\d\d\d', arg):
        rgb = short2rgb(arg)
        sys.stdout.write('xterm color \033[38;5;%sm%s\033[0m -> RGB exact \033[38;5;%sm%s\033[0m' % (arg, arg, arg, rgb))
        sys.stdout.write("\033[0m\n")
    else:
        arg = arg.lower().replace(' ', '')
        if not re.match('#?([0-9a-fA-F]{3}){1,2}', arg):
            try:
                arg = NAME_TO_HEX[arg]
            except KeyError:
                print >>sys.stderr, 'HTML name not known:', arg
                sys.exit(1)
        short, rgb = rgb2short(arg)
        sys.stdout.write('RGB %s -> xterm color approx \033[38;5;%sm%s (%s)' % (arg, short, short, rgb))
        sys.stdout.write("\033[0m\n")