Django custom filter example

from django.template import RequestContext
from django.shortcuts import render_to_response
def view(request)
    dicts = {"key1": 1, "key2": 2, "key3": 3, }
    return render_to_response("index.html",  {"dicts":dicts,},context_instance = RequestContext(request))

from django import template
register = template.Library()
def key(d,key_name):
        value = 0
        try:
                value = d[key_name]
        except KeyError:
                value = 0
        return value
register.filter('key',key)

{% load myfilter %} #加载自定认标签
{{dicts|key:"key1"}}