base string utility in python

base3

#! /usr/bin/python3
import sys
import os

INPUT = sys.argv[1]
RAW_STRING = None

if os.path.isfile(INPUT):
    RAW_STRING = open(INPUT).read().strip()
else:
    RAW_STRING = INPUT
    
def to_base3(n):
    if n == 0:
        return '0'
    nums = []
    while n:
        n, r = divmod(n, 3)
        nums.append(str(r))
    return ''.join(reversed(nums))

def string_to_base3(s):
    return ' '.join(to_base3(ord(c)) for c in s)

print(string_to_base3(RAW_STRING))