String formatting from template and nargs in python3

gen_from_template.py

import argparse

parser = argparse.ArgumentParser(description='generate script from template')
parser.add_argument('word', metavar='KEY=VALUE', type=str, nargs='+',
                   help='key-value pairs')
parser.add_argument('--template', metavar='input filename', type=str,
                   help='template file')
parser.add_argument('--output', metavar='output filename', type=str,
                   help='output')

args = parser.parse_args()
mydic = {}
for i in args.word:
    i = i.split('=')
    mydic[i[0]] = i[1]

with open(args.template, 'r') as f:
    text = f.read()
    text = text.format(**mydic)
    o = open(args.output, 'w')
    o.write(text + '\n')
    o.close()