Django内置filter总结

内置过滤器

目的是对绝大多数的内置过滤器进行测试总结学习,现设置如下:

urls.py中设置:

urlpatterns=[
url(r'^method',views.method,name='method'),
url(r'^$',TemplateView.as_view(template_name='banners/test.html',extra_context={'variable':'hello',other:'something'}),name='index'),
]

test.html中设置:

Strings,Numbers,Lists

'variable':'hello'

'variable':'3'

':variable':[1,2,3], 'other':[4,5]
{{ variable|add:other }}

**需要注意的是**不能在template中add:list

default
如果变量是false,不存在,或者空字符串,则用该过滤器来提供了一个缺省值.
':variable':''

':variable':False

default_if_none
仅对变量是None的进行缺省设置,对于空字符,False,不存在的不进行处理.
':variable':None

'variable':False

length

'variable':[1,2,3]
{{ variable|length }}

'variable':'abcd'
{{ variable|length }}

'variable':123
{{ variable|length }}

length_is
'variable':'abcd'
{{ variable|length_is:4 }}
或者{{ variable|length_is:'4' }}
make_list

'variable':'1234'
{{ variable|make_list }}

'variable':1234
{{ variable|make_list }}

yesno
yesno过滤器将True,False,None,映射为yes,no,maybe
'variable':True
{{ variable|yesno}}

Numbers

divisibleby
变量可被过滤器后参数整除,返回True,否则返回False,过滤器参数可为例如5,'5'.
'variable':20
{{ variable|divisibleby:'4' }}

'variable':'20'
{{ variable|divisibleby:'4' }}

filesizeformat

'variable':'250'
{{ variable|filesizeformat }}

'variable':200000
{{ variable|filesizeformat }}

floatformat
对浮点数小数点后的数字进行round,过滤器后参数可正可负,基本功能都一样,但对于比如9.000这样的数字而言,floatformat:3是9.000.而floatformat:-3是,默认是-1.
':variable':'3.1415'
{{ variable|filesizeformat }}
get_digit
获取数字某一位的值，1是最后一个，如果过滤器参数小于1，或者不是整数，那么输出全部数字，如果超过了位数，输出0.
'variable':12345
{{ variable|get_digit:3 }}

Strings

capfirst

':variable':'hello world'
{{ variable|capfirst }}

cut:

将string变量中出现的cut后的参数全部去除，返回剩下的部分

'variable':'asbscs’
{{ variable|cut:'s' }}

'variable':'a b c'
{{ variable|cut:' ' }}

linenumbers

'variable':"""a
b
c
d"""
{{ variable|cut:' ' }}

lower

将字符串变量的大写字母全部变成小写字母

"variable":"Hello World"
{{ variable|lower }}

stringformat

对于python，有 '%3d' % 7--->'007'
同样的，去掉'%'，
"variable":7
{{ variable|stringformat:'3d' }}

title

"variable":'hellor'
{{ variable|title }}

slugify

"variable":'hellor yes no'
{{ variable|slugify }}

truncatechars

"variable":'hellosjfdkls'
{{ variable|trancatechars:4 }}

truncatechar_html

"variable":'hellosjfdkls'
{{ variable|trancatechars_html:4 }}

truncatewords

"variable":'coffeehouse started as a small store'
{{ variable|trancatewords:3 }}

truncatewords_html

"variable":'coffeehouse started as a small store'
{{ variable|trancatewords:3 }}

upper

"variable":'coffeehouse started as a small store'
{{ variable|upper }}

wordcount

"variable":'coffeehouse started as a small store'
{{ variable|wordcount }}

Lists and Dictionaries

dictsort

'variable':[{'name':'Downtown','city':'san diego'},{'name':'Uptown','city':'san Diego'},{'name':'Midtown','city':'san Diego'},{'name':'Atown','city':'san Diego'}]

{% with newdict=variable|dictsort:'name' %}
{{ newdict }}
{% endwith %}
上例，对variable中的各dict中的'name'进行排序（按照字母），赋值给newdict后，显示newdict，当然也可以直接{{ variable|dictsort:'name'}}
dictsort过滤器也可以通过指明一个index编号来对包含多个元组的列表进行操作，比如{% with otherlist=listoftuples|dictsort:0 %}就是通过每个元组的第一个元素进行了重排。

dictsortreversed

'variable':[{'name':'Downtown','city':'san diego'},{'name':'Uptown','city':'san Diego'},{'name':'Midtown','city':'san Diego'},{'name':'Atown','city':'san Diego'}]

{% with newdict=variable|dictsortreversed:'name' %}
{{ newdict }}
{% endwith %}