Command line Jinja2 renderer

jj2.py

#!/usr/bin/env python
# -*- coding:utf8 -*-
import sys, optparse
import jinja2

def main(args, params):
    encoding = params.encoding
    tpl = jinja2.Template(sys.stdin.read().decode(encoding))
    param = dict()
    ex_args = list()
    for item in args:
        item = unicode(item, encoding)
        if '=' in item:
            k,v = item.split('=',1)
            param[k] = v
        else:
            ex_args.append(item)
    
    param['args'] = ex_args
    sys.stdout.write(tpl.render(param).encode(encoding))

if __name__ == '__main__':
    usage = """\
usage: %prog [-e encoding] [var1=value1 var2=value2 ...] [arg0 arg1 ...]

render jinja2 template string using given parameter.

example:
    $ echo "{{hello}} {{world}} {{args[0]}} !" | jj hello="Hello" world="World" "Foo"
    Hello World Foo !
"""
    parser = optparse.OptionParser(usage=usage)
    parser.add_option("-e", "--encoding",action="store", default="utf-8",help="character encoding (utf-8 default)")
    options, args = parser.parse_args()
    main(args, options)