Double helix ascii printer

dblhelix

#!/usr/bin/env python2

"""
    Double Helix Text
"""

import argparse
import math
import sys
import time

from itertools import cycle
from pprint import pprint

DEFAULT = "(='.'=)"

ARGP = argparse.ArgumentParser(
    description=__doc__,
    formatter_class=argparse.RawTextHelpFormatter,
)
ARGP.add_argument('text', nargs='?', help='Input String', default=DEFAULT)

def strput(ob, offset, text):
    for i, v in enumerate(text):
        ob[offset+i] = v

def main(argp=None):
    if argp is None:
        argp = ARGP.parse_args()

    width = len(argp.text) + 2

    step = math.pi * 2 / width
    steps = []
    for x in xrange(1, width + 1):
        steps.append(int(round(math.sin(step * x) * width/2) + width))

    pos = cycle(steps)

    delta = None
    while True:
        offset = pos.next()
        ob = [' '] * (width*3);
        if delta is None:
            delta = offset
        else:
            delta = offset - last

        if delta >= 0:
            strput(ob, offset, argp.text)

        strput(ob, (width*2)-offset, argp.text)

        if delta < 0:
            strput(ob, offset, argp.text)

        sys.stdout.write(''.join(ob) + '\n')
        sys.stdout.flush()

        last = offset
        time.sleep(0.1)

if __name__ == '__main__':
    main()