Python系列视频教程: Django【13讲】第四讲运算符-表达式

最新推荐文章于 2024-12-05 07:14:07 发布

cajan2

最新推荐文章于 2024-12-05 07:14:07 发布

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Python系列视频教程: Django【13讲】第四讲运算符-表达式

step1：模板标签的使用

mytag.html

使用条件标签

<body>
{% if %}
{% else%}
{% endif %}

</body>

<body>
{% if user%}
<h1>name: {{user.name}}</h1>
{% else%}
user not exist用户不存在
{% endif %}

</body>

def mytag(req):
#user={'name':'tom','age':23,'sex':'male'}
user=Person('Alexander',35,'male')
book_list=['python','java','php','web']
return render_to_response('mytag.html',{'title':'my page','book_list':book_list})

user not exist用户不存在

下面去查看api文档

https://docs.djangoproject.com/en/1.6/ref/templates/builtins/#if

Use of both and andor clauses within the same tag is allowed, withand having higher precedence thanor e.g.:

{% if athlete_list and coach_list or cheerleader_list %}

will be interpreted like:

 
  if (athlete_list and coach_list) or cheerleader_list

Use of actual parentheses in the if tag is invalid syntax. If you need them to indicate precedence, you should use nestedif tags.

> < == != >= <=

not in

step2：使用for循环

{% for book in book_list %}
<li>book:{{book}}</li>
{% endfor %}

user not exist用户不存在

the say:

book:python
book:java
book:php
book:web

step3：对字典的遍历

恢复user变量的传递

原先的字典改名为user_dict，一起传递

def mytag(req):
user_dict={'name':'tom','age':23,'sex':'male'}
user=Person('Alexander',35,'male')
book_list=['python','java','php','web']
return render_to_response('mytag.html',{'title':'my page','user':user,'book_list':book_list,'user_dict':user_dict})

mytag.html

<body>
{% if user%}
<h1>name: {{user.name}}</h1>
{% else%}
user not exist用户不存在
{% endif %}
<div>
the {{user.name}} say:{{user.say}}
</div>
{% for book in book_list %}
<li>book:{{book}}</li>
{% endfor %}
{% for k in user_dict %}
<li>user_dict:{{k}}</li>
{% endfor %}
</body>

http://127.0.0.1:8000/blog/mytag/

name: Alexander

the Alexander say:I'm Alexander
book:python
book:java
book:php
book:web
user_dict:age
user_dict:name
user_dict:sex

使用KV对

{% for k,v in user_dict.items %}
<li>{{k}}:{{v}}</li>
{% endfor %}

name: Alexander

the Alexander say:I'm Alexander
book:python
book:java
book:php
book:web
age:23
name:tom

sex:male

step4：for的进一步使用

for

The for loop sets a number of variables available within the loop:

Variable	Description
`forloop.counter`	The current iteration of the loop (1-indexed)
`forloop.counter0`	The current iteration of the loop (0-indexed)
`forloop.revcounter`	The number of iterations from the end of the loop (1-indexed)
`forloop.revcounter0`	The number of iterations from the end of the loop (0-indexed)
`forloop.first`	True if this is the first time through the loop
`forloop.last`	True if this is the last time through the loop
`forloop.parentloop`	For nested loops, this is the loop surrounding the current one

{% for k,v in user_dict.items %}
<li>{{forloop.counter}}.{{k}}:{{v}}</li>
{% endfor %}

name: Alexander

the Alexander say:I'm Alexander

book:python
book:java
book:php
book:web
1.age:23
2.name:tom
3.sex:male
使用empty

optional {% empty %} clause whose text is displayed if the given array is empty or could not be found:

{% for k,v in user_dict.items %}
<li>{{forloop.counter}}.{{k}}:{{v}}</li>
{% empty %}
<li>Sorry, no user in this list.</li>

{% endfor %}