django 自定义过滤器的实现

- book
  - views.py
  - urls.py
  - models.py
  - templatetags
    - my_filter.py

from django import template

# 创建模板库对象
register = template.Library()

# 过滤器函数
def mycut(value,mystr):
  return value.replace(mystr)
# 将函数注册到模板库中
register.filter("mycut",mycut)

{% load my_filter %}

# time_filter.py文件

from datetime import datetime
from django import template

register = template.Library()

def time_since(value):
  """
  time距离现在的时间间隔
  1\. 如果时间间隔小于1分钟以内，那么就显示“刚刚”
  2\. 如果是大于1分钟小于1小时，那么就显示“xx分钟前”
  3\. 如果是大于1小时小于24小时，那么就显示“xx小时前”
  4\. 如果是大于24小时小于30天以内，那么就显示“xx天前”
  5\. 否则就是显示具体的时间 2017/10/20 16:15
  """
  if isinstance(value,datetime):
    now = datetime.now()
    timestamp = (now - value).total_seconds()
    if timestamp < 60:
      return "刚刚"
    elif timestamp >= 60 and timestamp < 60*60:
      minutes = int(timestamp / 60)
      return "%s分钟前" % minutes
    elif timestamp >= 60*60 and timestamp < 60*60*24:
      hours = int(timestamp / (60*60))
      return "%s小时前" % hours
    elif timestamp >= 60*60*24 and timestamp < 60*60*24*30:
      days = int(timestamp / (60*60*24))
      return "%s天前" % days
    else:
      return value.strftime("%Y/%m/%d %H:%M")
  else:
    return value

register.filter("time_since",time_since)

{% load time_filter %}
...
{% value|time_since %}
...

from django import template
register = template.Library()

@register.filter(name='mycut')
def mycut(value,mystr):
  return value.replace(mystr,"")