reponse对象(响应对象)

星哥玩云

发布于 2022-09-14 18:48:04

7700

发布于 2022-09-14 18:48:04

文章被收录于专栏：开源部署开源部署

一、作用

返回给客户端的信息

2、概述

request对象是有服务创建的，response对象需要程序员手动创建

3、创建response对象

导入 from flask import make_response

原型 def make_response(*args): def make_response(info, status, headers):

参数 info 必选参数返回的数据 status 可选参数响应状态码 headers 可选参数子主题

示例

<span class="hljs-meta">@app.route("/res/")</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">res</span><span class="hljs-params">()</span>:</span>
    response = make_response(<span class="hljs-string">"lucky is a good man"</span>, <span class="hljs-number">200</span>, {<span class="hljs-string">"Content-Type"</span>: <span class="hljs-string">"text/plain; charset=utf-8"</span>})
    <span class="hljs-keyword">return</span> response

注意

可以直接返回一个字符串，flask会自动包装成response对象

4、响应数据

返回字符串数据

<span class="hljs-meta">@app.route("/res1/")</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">res</span><span class="hljs-params">()</span>:</span>
    response = make_response(<span class="hljs-string">"lucky is a good man"</span>, <span class="hljs-number">200</span>, {<span class="hljs-string">"Content-Type"</span>: <span class="hljs-string">"text/plain; charset=utf-8"</span>})
    <span class="hljs-keyword">return</span> response

返回json数据

<span class="hljs-keyword">from</span> flask <span class="hljs-keyword">import</span> json
<span class="hljs-meta">@myApp.route("/res2/")</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">res3</span><span class="hljs-params">()</span>:</span>
    <span class="hljs-keyword">return</span> jsonify({<span class="hljs-string">'name'</span>:<span class="hljs-string">'lucky'</span>, <span class="hljs-string">'age'</span>:<span class="hljs-number">18</span>})

返回页面

<span class="hljs-meta">@myApp.route("/res3/")</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">res3</span><span class="hljs-params">()</span>:</span>
    <span class="hljs-keyword">return</span> render_template(<span class="hljs-string">"index.html"</span>)

5、状态码

作用

告诉客户端对于请求处理结果的状态

使用方式

方式一

<span class="hljs-meta">@myApp.route("/res4/")</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">res4</span><span class="hljs-params">()</span>:</span>
    response = make_response(<span class="hljs-string">"lucky is a good man"</span>, <span class="hljs-number">999</span>)
    <span class="hljs-keyword">return</span> response

方式二

<span class="hljs-meta">@myApp.route("/res4/")</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">res4</span><span class="hljs-params">()</span>:</span>
    response = make_response(<span class="hljs-string">"lucky is a good man"</span>)
    <span class="hljs-keyword">return</span> response,<span class="hljs-number">999</span>

6、重定向与反向解析

重定向作用

可以直接通知浏览器转向到另一个地址

导入

from flask import redirect,url_for

redirect：重定向通过传递路由地址参数进行重定向跳转

url_for：反向解析将当前的视图函数名称反向构造出路由地址

redirect 重定向使用

<span class="hljs-comment"># 使用redirect</span>
<span class="hljs-meta">@app.route('/redirect/')</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">my_redirect</span><span class="hljs-params">()</span>:</span>
		<span class="hljs-comment"># 去首页 无参路由</span>
    <span class="hljs-keyword">return</span> redirect(<span class="hljs-string">'/'</span>)
		<span class="hljs-comment"># 带一个参数的路由地址的重定向</span>
    <span class="hljs-keyword">return</span> redirect(<span class="hljs-string">'/arg/lucky/'</span>)
		<span class="hljs-comment"># 带多个参数的路由地址的重定向</span>
    <span class="hljs-keyword">return</span> redirect(<span class="hljs-string">'/args/lucky/18/'</span>)

url_for 反向解析使用

<span class="hljs-comment"># 使用url_for 的视图函数</span>
<span class="hljs-meta">@app.route('/url_for/')</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">my_urlfor</span><span class="hljs-params">()</span>:</span>
    <span class="hljs-comment"># 构造首页路由</span>
    print(url_for(<span class="hljs-string">'index'</span>))  <span class="hljs-comment"># /</span>
    <span class="hljs-comment"># 给url_for 一个带参的视图函数 但是没给参数  会报错werkzeug.routing.BuildError: Could not build url for endpoint 'arg'. Did you forget to specify values ['name']?</span>
    print(url_for(<span class="hljs-string">'arg'</span>))
    <span class="hljs-comment"># 带一个参数  给参数</span>
    print(url_for(<span class="hljs-string">'arg'</span>,name=<span class="hljs-string">'lucky'</span>)) <span class="hljs-comment"># /arg/lucky/</span>
    <span class="hljs-comment"># 带多个参数的视图函数</span>
    <span class="hljs-comment"># werkzeug.routing.BuildError: Could not build url for endpoint 'args'. Did you forget to specify values ['age', 'name']?</span>
    print(url_for(<span class="hljs-string">'args'</span>))
    <span class="hljs-comment"># 带参数</span>
    print(url_for(<span class="hljs-string">'args'</span>,name=<span class="hljs-string">'lucky'</span>,age=<span class="hljs-number">18</span>)) <span class="hljs-comment">#/args/lucky/18/</span>
    <span class="hljs-keyword">return</span> <span class="hljs-string">'url_for'</span>

redirect和url_for的组合使用

<span class="hljs-comment"># redirect 和 url_for的组合使用</span>
<span class="hljs-meta">@app.route('/ru/')</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">ru</span><span class="hljs-params">()</span>:</span>
    <span class="hljs-comment"># 去首页</span>
    <span class="hljs-keyword">return</span> redirect(url_for(<span class="hljs-string">'index'</span>))
    <span class="hljs-comment"># 去一个参数的路由地址</span>
    <span class="hljs-keyword">return</span> redirect(url_for(<span class="hljs-string">'arg'</span>,name=<span class="hljs-string">'lucky'</span>))
    <span class="hljs-comment"># 去多个参数的路由地址</span>
    <span class="hljs-keyword">return</span> redirect(url_for(<span class="hljs-string">'args'</span>,name=<span class="hljs-string">'lucky'</span>,age=<span class="hljs-number">18</span>))

7、终止执行

概述

如果是视图函数执行过程中出现了错误，可以通过abort函数立即终止视图函数的执行
通过abort函数，可以向前端返回一个http标准中存在的状态码，表示出现的错误信息。使用abort函数返回http标准中不存在的状态码是没有任何实际意义的
如果触发了abort函数，那么其后面的代码不会被执行类似于python中的raise

导入

from flask import abort

使用

<span class="hljs-comment"># 终止</span>
<span class="hljs-meta">@app.route('/abort/')</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">err</span><span class="hljs-params">()</span>:</span>
    <span class="hljs-comment"># 使用abort函数不是说控制权就归你了，它只是向系统抛出了指定的异常</span>
    <span class="hljs-comment"># 异常的处理仍然会按照框架中写好方式进行</span>
    abort(<span class="hljs-number">404</span>)
    <span class="hljs-keyword">return</span> <span class="hljs-string">'abort测试'</span>

<span class="hljs-comment"># 错误页面定制</span>
<span class="hljs-meta">@app.errorhandler(404)</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">page_not_found</span><span class="hljs-params">(err)</span>:</span>
    <span class="hljs-keyword">return</span> err
<span class="hljs-string">"""
Not Found
The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
"""</span>

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