Retro ANSI colors

colors.py

'''
    Set ANSI Terminal Color and Attributes.

    http://code.activestate.com/recipes/574451-handling-ansi-terminal/

'''
from sys import stdout

esc = '%s['%chr(27)
reset = '%s0m'%esc
format = '1;%dm'
fgoffset, bgoffset = 30, 40
for k, v in dict(
    attrs = 'none bold faint italic underline blink fast reverse concealed',
    colors = 'grey red green yellow blue magenta cyan white'
).items(): globals()[k]=dict((s,i) for i,s in enumerate(v.split()))

def echo(arg=None, sep=' ', end='\n'):
    '''
        "arg" is a string or None
        if "arg" is None : the terminal is reset to his default values.
        if "arg" is a string it must contain "sep" separated values.
        if args are found in globals "attrs" or "colors", or start with "@" \
    they are interpreted as ANSI commands else they are output as text.
        colors, if any, must be first (foreground first then background)
        you can not specify a background color alone ; \
    if you specify only one color, it will be the foreground one.
        @* commands handle the screen and the cursor :
            @x;y : go to xy
            @    : go to 1;1
            @@   : clear screen and go to 1;1

        examples:
    echo('red')                  : set red as the foreground color
    echo('red blue')             : red on blue
    echo('red blink')            : blinking red
    echo()                       : restore terminal default values
    echo('reverse')              : swap default colors
    echo('cyan blue reverse')    : blue on cyan <=> echo('blue cyan)
    echo('red reverse')          : a way to set up the background only
    echo('red reverse blink')    : you can specify any combinaison of \
            attributes in any order with or without colors
    echo('blink Python')         : output a blinking 'Python'
    echo('@@ hello')             : clear the screen and print 'hello' at 1;1
    '''

    cmd, txt = [reset], []
    if arg:
        arglist=arg.split(sep)
        for offset in (fgoffset, bgoffset):
            if arglist and arglist[0] in colors:
                cmd.append(format % (colors[arglist.pop(0)]+offset))
        for a in arglist:
            c=format % attrs[a] if a in attrs else None
            if c and c not in cmd:
                cmd.append(c)
            else:
                if a.startswith('@'):
                    a=a[1:]
                    if a=='@':
                        cmd.append('2J')
                        cmd.append('H')
                    else:
                        cmd.append('%sH'%a)
                else:
                    txt.append(a)
    if txt and end: txt[-1]+=end
    stdout.write(esc.join(cmd)+sep.join(txt))

if __name__ == '__main__':

    echo('@@ reverse blink')
    print 'reverse blink  default colors at 1;1 on a cleared screen'
    echo('red')
    print 'red'
    echo('red blue')
    print 'red blue'
    echo('yellow blink')
    print 'yellow blink'
    echo('default')
    echo('cyan blue cyan blue')
    echo('cyan blue reverse cyan blue reverse')
    echo('blue cyan blue cyan')
    echo('red reverse red reverse')
    echo('yellow red yellow on red 1')
    echo('yellow,red,yellow on red 2', sep=',')
    print 'yellow on red 3'
    print
    for bg in colors:
        echo(bg.title().center(8), sep='.', end='')
        for fg in colors:
            att=[fg, bg]
            if fg==bg: att.append('blink')
            att.append(fg.center(8))
            echo(','.join(att), sep=',', end='')
        print
    print
    for att in attrs:
        echo('%s,%s' % (att, att.title().center(10)), sep=',', end='')
    print
    from time import sleep, strftime, gmtime
    colist='grey blue cyan white cyan blue'.split()
    while True:
        try:
            for c in colist:
                sleep(.1)
                echo('%s @28;33 hit ctrl-c to quit' % c)
            echo('yellow @6;66 %s' % strftime('%H:%M:%S', gmtime()))
        except KeyboardInterrupt:
            break
        except:
            raise
    echo('@30;1')
    print