Django snippets

def some_function(db, handle):
    return db.some_method(handle)

class TemplateNode(template.Node):
    def __init__(self, args, var_name, func):
        self.args = map(template.Variable, args)
        self.var_name = var_name
        self.func = func

    def render(self, context):
        value = self.func(*[item.resolve(context) for item in self.args])
        if self.var_name:
            context[self.var_name] = value
            return ''
        else:
            return value

def parse_tokens(tokens):
    items = tokens.contents.split(None)
    # {% tag_name arg1 arg2 arg3 as variable %}
    # {% tag_name arg1 arg2 arg3 %}
    tag_name = items[0]
    if "as" == items[-2]:
        var_name = items[-1]
        args = items[1:-2]
    else:
        var_name = None
        args = items[1:]
    return (tag_name, args, var_name)

def make_tag(func):
    def do_func(parser, tokens):
        tag_name, args, var_name = parse_tokens(tokens)
        return TemplateNode(args, var_name, func)
    return do_func

register.tag("some_function", 
             make_tag(some_function))