base64 encoder and decoder for python3.x

basesixtyfour.py

#!/usr/local/bin/python
#coding:utf-8

import sys
import base64

def s2b64_encode(file):
    #bytes -> base64
    
    #in  filename(string)
    #out bytes(base64)
    return base64.b64encode(open(file, 'rb').read())

def s2b64_decode(dbytes):
    #base64 -> bytes -> string
    
    #in  bytes
    #out string
    return bytes.decode(base64.b64decode(dbytes))

if __name__ == '__main__':
    
    arg  = sys.argv
    base = s2b64_encode(arg[1])
    print(base)