katex for facebook messenger

rainbow.py

#!/bin/python3
import sys

if len(sys.argv) < 2:
    l = 'sample text'
else:
    l = " ".join(sys.argv[1:])

colors = ['#ff0000',
        '#ff7f00',
        '#ffff00',
        '#00ff00',
        '#0000ff',
        '#4b0082',
        '#9400d3']

print('$$', end='', sep='')
for i in range(len(l)):
    if l[i].isspace():
        print('\\text{',l[i],'}', end='', sep='')
    else:
        print('\color{',colors[i%len(colors)],'}\\text{',l[i],'}', end='', sep='')
print('$$')