Python教程
Python之路【第十八篇】：Web框架们
本文主要是介绍Python之路【第十八篇】：Web框架们，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！
Python的WEB框架
Bottle
Bottle是一个快速、简洁、轻量级的基于WSIG的微型Web框架，此框架只由一个 .py 文件，除了Python的标准库外，其不依赖任何其他模块。
| 1 2 3 4 |
pip install bottle
easy_install bottle
apt-get install python-bottle
wget http://bottlepy.org/bottle.py
|
Bottle框架大致可以分为以下部分：
- 路由系统，将不同请求交由指定函数处理
- 模板系统，将模板中的特殊语法渲染成字符串，值得一说的是Bottle的模板引擎可以任意指定：Bottle内置模板、mako、jinja2、cheetah
- 公共组件，用于提供处理请求相关的信息，如：表单数据、cookies、请求头等
- 服务，Bottle默认支持多种基于WSGI的服务，如：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 server_names={'cgi': CGIServer,'flup': FlupFCGIServer,'wsgiref': WSGIRefServer,'waitress': WaitressServer,'cherrypy': CherryPyServer,'paste': PasteServer,'fapws3': FapwsServer,'tornado': TornadoServer,'gae': AppEngineServer,'twisted': TwistedServer,'diesel': DieselServer,'meinheld': MeinheldServer,'gunicorn': GunicornServer,'eventlet': EventletServer,'gevent': GeventServer,'geventSocketIO':GeventSocketIOServer,'rocket': RocketServer,'bjoern': BjoernServer,'auto': AutoServer,}
框架的基本使用
| 1 2 3 4 5 6 7 8 9 10 11 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from bottle import template, Bottle
root = Bottle()
@root.route('/hello/')
def index():
return "Hello World"
# return template('<b>Hello {{name}}</b>!', name="Alex")
root.run(host='localhost', port=8080)
|
一、路由系统
路由系统是的url对应指定函数，当用户请求某个url时，就由指定函数处理当前请求，对于Bottle的路由系统可以分为一下几类：
- 静态路由
- 动态路由
- 请求方法路由
- 二级路由
1、静态路由
| 1 2 3 |
@root.route('/hello/')
def index():
return template('<b>Hello {{name}}</b>!', name="Alex")
|
2、动态路由
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
@root.route('/wiki/<pagename>')
def callback(pagename):
...
@root.route('/object/<id:int>')
def callback(id):
...
@root.route('/show/<name:re:[a-z]+>')
def callback(name):
...
@root.route('/static/<path:path>')
def callback(path):
return static_file(path, root='static')
|
3、请求方法路由
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 |
@root.route('/hello/', method='POST')
def index():
...
@root.get('/hello/')
def index():
...
@root.post('/hello/')
def index():
...
@root.put('/hello/')
def index():
...
@root.delete('/hello/')
def index():
...
|
4、二级路由
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 from bottle import template, Bottle
4
5 app01 = Bottle()
6
7 @app01.route('/hello/', method='GET')
8 def index():
9 return template('<b>App01</b>!')
app01.py
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 from bottle import template, Bottle
4
5 app02 = Bottle()
6
7
8 @app02.route('/hello/', method='GET')
9 def index():
10 return template('<b>App02</b>!')
app02.py
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from bottle import template, Bottle
from bottle import static_file
root = Bottle()
@root.route('/hello/')
def index():
return template('<b>Root {{name}}</b>!', name="Alex")
from framwork_bottle import app01
from framwork_bottle import app02
root.mount('app01', app01.app01)
root.mount('app02', app02.app02)
root.run(host='localhost', port=8080)
|
二、模板系统
模板系统用于将Html和自定的值两者进行渲染，从而得到字符串，然后将该字符串返回给客户端。我们知道在Bottle中可以使用 内置模板系统、mako、jinja2、cheetah等，以内置模板系统为例：
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 </head>
7 <body>
8 <h1>{{name}}</h1>
9 </body>
10 </html>
hello_template.tpl
| 1 2 3 4 5 6 7 8 9 10 11 12 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from bottle import template, Bottle
root = Bottle()
@root.route('/hello/')
def index():
# 默认情况下去目录：['./', './views/']中寻找模板文件 hello_template.html
# 配置在 bottle.TEMPLATE_PATH 中
return template('hello_template.tpl', name='alex')
root.run(host='localhost', port=8080)
|
1、语法
- 单值
- 单行Python代码
- Python代码快
- Python、Html混合
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
<h1>1、单值</h1>
{{name}}
<h1>2、单行Python代码</h1>
% s1 = "hello"
<h1>3、Python代码块</h1>
<%
# A block of python code
name = name.title().strip()
if name == "Alex":
name="seven"
%>
<h1>4、Python、Html混合</h1>
% if True:
<span>{{name}}</span>
% end
<ul>
% for item in name:
<li>{{item}}</li>
% end
</ul>
|
2、函数
include(sub_template, **variables)
| 1 2 3 4 5 |
# 导入其他模板文件
% include('header.tpl', title='Page Title')
Page Content
% include('footer.tpl')
|
rebase(name, **variables)
1 <html>
2 <head>
3 <title>{{title or 'No title'}}</title>
4 </head>
5 <body>
6 {{!base}}
7 </body>
8 </html>
base.tpl
| 1 2 3 4 |
# 导入母版
% rebase('base.tpl', title='Page Title')
<p>Page Content ...</p>
|
defined(name)
| 1 |
# 检查当前变量是否已经被定义，已定义True，未定义False
|
get(name, default=None)
| 1 |
# 获取某个变量的值，不存在时可设置默认值
|
setdefault(name, default)
| 1 |
# 如果变量不存在时，为变量设置默认值
|
扩展：自定义函数
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 </head>
7 <body>
8 <h1>自定义函数</h1>
9 {{ wupeiqi() }}
10
11 </body>
12 </html>
hello_template.tpl
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 from bottle import template, Bottle,SimpleTemplate
4 root = Bottle()
5
6
7 def custom():
8 return '123123'
9
10
11 @root.route('/hello/')
12 def index():
13 # 默认情况下去目录：['./', './views/']中寻找模板文件 hello_template.html
14 # 配置在 bottle.TEMPLATE_PATH 中
15 return template('hello_template.html', name='alex', wupeiqi=custom)
16
17 root.run(host='localhost', port=8080)
main.py
注：变量或函数前添加 【 ! 】，则会关闭转义的功能
三、公共组件
由于Web框架就是用来【接收用户请求】-> 【处理用户请求】-> 【响应相关内容】，对于具体如何处理用户请求，开发人员根据用户请求来进行处理，而对于接收用户请求和相应相关的内容均交给框架本身来处理，其处理完成之后将产出交给开发人员和用户。
【接收用户请求】
当框架接收到用户请求之后，将请求信息封装在Bottle的request中，以供开发人员使用
【响应相关内容】
当开发人员的代码处理完用户请求之后，会将其执行内容相应给用户，相应的内容会封装在Bottle的response中，然后再由框架将内容返回给用户
所以，公共组件本质其实就是为开发人员提供接口，使其能够获取用户信息并配置响应内容。
1、request
Bottle中的request其实是一个LocalReqeust对象，其中封装了用户请求的相关信息：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
request.headers
请求头信息
request.query
get请求信息
request.forms
post请求信息
request.files
上传文件信息
request.params
get和post请求信息
request.GET
get请求信息
request.POST
post和上传信息
request.cookies
cookie信息
request.environ
环境相关相关
|
2、response
Bottle中的request其实是一个LocalResponse对象，其中框架即将返回给用户的相关信息：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
response
response.status_line
状态行
response.status_code
状态码
response.headers
响应头
response.charset
编码
response.set_cookie
在浏览器上设置cookie
response.delete_cookie
在浏览器上删除cookie
|
实例：
1 from bottle import route, request
2
3 @route('/login')
4 def login():
5 return '''
6 <form action="/login" method="post">
7 Username: <input name="username" type="text" />
8 Password: <input name="password" type="password" />
9 <input value="Login" type="submit" />
10 </form>
11 '''
12
13 @route('/login', method='POST')
14 def do_login():
15 username = request.forms.get('username')
16 password = request.forms.get('password')
17 if check_login(username, password):
18 return "<p>Your login information was correct.</p>"
19 else:
20 return "<p>Login failed.</p>"
基本Form请求
1 <form action="/upload" method="post" enctype="multipart/form-data">
2 Category: <input type="text" name="category" />
3 Select a file: <input type="file" name="upload" />
4 <input type="submit" value="Start upload" />
5 </form>
6
7
8 @route('/upload', method='POST')
9 def do_upload():
10 category = request.forms.get('category')
11 upload = request.files.get('upload')
12 name, ext = os.path.splitext(upload.filename)
13 if ext not in ('.png','.jpg','.jpeg'):
14 return 'File extension not allowed.'
15
16 save_path = get_save_path_for_category(category)
17 upload.save(save_path) # appends upload.filename automatically
18 return 'OK'
上传文件
四、服务
对于Bottle框架其本身未实现类似于Tornado自己基于socket实现Web服务，所以必须依赖WSGI，默认Bottle已经实现并且支持的WSGI有：
1 server_names = {
2 'cgi': CGIServer,
3 'flup': FlupFCGIServer,
4 'wsgiref': WSGIRefServer,
5 'waitress': WaitressServer,
6 'cherrypy': CherryPyServer,
7 'paste': PasteServer,
8 'fapws3': FapwsServer,
9 'tornado': TornadoServer,
10 'gae': AppEngineServer,
11 'twisted': TwistedServer,
12 'diesel': DieselServer,
13 'meinheld': MeinheldServer,
14 'gunicorn': GunicornServer,
15 'eventlet': EventletServer,
16 'gevent': GeventServer,
17 'geventSocketIO':GeventSocketIOServer,
18 'rocket': RocketServer,
19 'bjoern' : BjoernServer,
20 'auto': AutoServer,
21 }
WSGI
使用时，只需在主app执行run方法时指定参数即可：
| 1 2 3 4 5 6 7 8 9 10 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from bottle import Bottle
root = Bottle()
@root.route('/hello/')
def index():
return "Hello World"
# 默认server ＝'wsgiref'
root.run(host='localhost', port=8080, server='wsgiref')
|
默认server＝"wsgiref"，即：使用Python内置模块wsgiref，如果想要使用其他时，则需要首先安装相关类库，然后才能使用。如：
1 # 如果使用Tornado的服务，则需要首先安装tornado才能使用 2 3 class TornadoServer(ServerAdapter): 4 """ The super hyped asynchronous server by facebook. Untested. """ 5 def run(self, handler): # pragma: no cover 6 # 导入Tornado相关模块 7 import tornado.wsgi, tornado.httpserver, tornado.ioloop 8 container = tornado.wsgi.WSGIContainer(handler) 9 server = tornado.httpserver.HTTPServer(container) 10 server.listen(port=self.port,address=self.host) 11 tornado.ioloop.IOLoop.instance().start()bottle.py源码
PS：以上WSGI中提供了19种，如果想要使期支持其他服务，则需要扩展Bottle源码来自定义一个ServerAdapter
更多参见：http://www.bottlepy.org/docs/dev/index.html
Flask
Flask是一个基于Python开发并且依赖jinja2模板和Werkzeug WSGI服务的一个微型框架，对于Werkzeug本质是Socket服务端，其用于接收http请求并对请求进行预处理，然后触发Flask框架，开发人员基于Flask框架提供的功能对请求进行相应的处理，并返回给用户，如果要返回给用户复杂的内容时，需要借助jinja2模板来实现对模板的处理，即：将模板和数据进行渲染，将渲染后的字符串返回给用户浏览器。
“微”(micro) 并不表示你需要把整个 Web 应用塞进单个 Python 文件（虽然确实可以 ），也不意味着 Flask 在功能上有所欠缺。微框架中的“微”意味着 Flask 旨在保持核心简单而易于扩展。Flask 不会替你做出太多决策——比如使用何种数据库。而那些 Flask 所选择的——比如使用何种模板引擎——则很容易替换。除此之外的一切都由可由你掌握。如此，Flask 可以与您珠联璧合。
默认情况下，Flask 不包含数据库抽象层、表单验证，或是其它任何已有多种库可以胜任的功能。然而，Flask 支持用扩展来给应用添加这些功能，如同是 Flask 本身实现的一样。众多的扩展提供了数据库集成、表单验证、上传处理、各种各样的开放认证技术等功能。Flask 也许是“微小”的，但它已准备好在需求繁杂的生产环境中投入使用。
安装
| 1 |
pip install Flask
|
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 from werkzeug.wrappers import Request, Response
4
5 @Request.application
6 def hello(request):
7 return Response('Hello World!')
8
9 if __name__ == '__main__':
10 from werkzeug.serving import run_simple
11 run_simple('localhost', 4000, hello)
werkzeug
一、第一次
| 1 2 3 4 5 6 7 8 9 |
from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello():
return "Hello World!"
if __name__ == "__main__":
app.run()
|
二、路由系统
- @app.route('/user/<username>')
- @app.route('/post/<int:post_id>')
- @app.route('/post/<float:post_id>')
- @app.route('/post/<path:path>')
- @app.route('/login', methods=['GET', 'POST'])
常用路由系统有以上五种，所有的路由系统都是基于一下对应关系来处理：
| 1 2 3 4 5 6 7 8 9 |
DEFAULT_CONVERTERS = {
'default': UnicodeConverter,
'string': UnicodeConverter,
'any': AnyConverter,
'path': PathConverter,
'int': IntegerConverter,
'float': FloatConverter,
'uuid': UUIDConverter,
}
|
注：对于Flask默认不支持直接写正则表达式的路由，不过可以通过自定义来实现，见：https://segmentfault.com/q/1010000000125259
三、模板
1、模板的使用
Flask使用的是Jinja2模板，所以其语法和Django无差别
2、自定义模板方法
Flask中自定义模板方法的方式和Bottle相似，创建一个函数并通过参数的形式传入render_template，如：
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 </head>
7 <body>
8 <h1>自定义函数</h1>
9 {{ww()|safe}}
10
11 </body>
12 </html>
index.html
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Flask,render_template
app = Flask(__name__)
def wupeiqi():
return '<h1>Wupeiqi</h1>'
@app.route('/login', methods=['GET', 'POST'])
def login():
return render_template('login.html', ww=wupeiqi)
app.run()
|
四、公共组件
1、请求
对于Http请求，Flask会讲请求信息封装在request中(werkzeug.wrappers.BaseRequest)，提供的如下常用方法和字段以供使用：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
request.method
request.args
request.form
request.values
request.files
request.cookies
request.headers
request.path
request.full_path
request.script_root
request.url
request.base_url
request.url_root
request.host_url
request.host
|
1 @app.route('/login', methods=['POST', 'GET'])
2 def login():
3 error = None
4 if request.method == 'POST':
5 if valid_login(request.form['username'],
6 request.form['password']):
7 return log_the_user_in(request.form['username'])
8 else:
9 error = 'Invalid username/password'
10 # the code below is executed if the request method
11 # was GET or the credentials were invalid
12 return render_template('login.html', error=error)
表单处理Demo
1 from flask import request
2 from werkzeug import secure_filename
3
4 @app.route('/upload', methods=['GET', 'POST'])
5 def upload_file():
6 if request.method == 'POST':
7 f = request.files['the_file']
8 f.save('/var/www/uploads/' + secure_filename(f.filename))
9 ...
上传文件Demo
1 from flask import request
2
3 @app.route('/setcookie/')
4 def index():
5 username = request.cookies.get('username')
6 # use cookies.get(key) instead of cookies[key] to not get a
7 # KeyError if the cookie is missing.
8
9
10
11
12 from flask import make_response
13
14 @app.route('/getcookie')
15 def index():
16 resp = make_response(render_template(...))
17 resp.set_cookie('username', 'the username')
18 return resp
Cookie操作
2、响应
当用户请求被开发人员的逻辑处理完成之后，会将结果发送给用户浏览器，那么就需要对请求做出相应的响应。
a.字符串
| 1 2 3 |
@app.route('/index/', methods=['GET', 'POST'])
def index():
return "index"
|
b.模板引擎
| 1 2 3 4 5 6 7 8 |
from flask import Flask,render_template,request
app = Flask(__name__)
@app.route('/index/', methods=['GET', 'POST'])
def index():
return render_template("index.html")
app.run()
|
c.重定向
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Flask, redirect, url_for
app = Flask(__name__)
@app.route('/index/', methods=['GET', 'POST'])
def index():
# return redirect('/login/')
return redirect(url_for('login'))
@app.route('/login/', methods=['GET', 'POST'])
def login():
return "LOGIN"
app.run()
|
d.错误页面
1 from flask import Flask, abort, render_template
2 app = Flask(__name__)
3
4 @app.route('/e1/', methods=['GET', 'POST'])
5 def index():
6 abort(404, 'Nothing')
7 app.run()
指定URL，简单错误
| 1 2 3 4 5 6 7 8 9 10 11 12 |
from flask import Flask, abort, render_template
app = Flask(__name__)
@app.route('/index/', methods=['GET', 'POST'])
def index():
return "OK"
@app.errorhandler(404)
def page_not_found(error):
return render_template('page_not_found.html'), 404
app.run()
|
e.设置相应信息
使用make_response可以对相应的内容进行操作
| 1 2 3 4 5 6 7 8 9 10 11 12 13 |
from flask import Flask, abort, render_template,make_response
app = Flask(__name__)
@app.route('/index/', methods=['GET', 'POST'])
def index():
response = make_response(render_template('index.html'))
# response是flask.wrappers.Response类型
# response.delete_cookie
# response.set_cookie
# response.headers['X-Something'] = 'A value'
return response
app.run()
|
3、Session
除请求对象之外，还有一个 session 对象。它允许你在不同请求间存储特定用户的信息。它是在 Cookies 的基础上实现的，并且对 Cookies 进行密钥签名要使用会话，你需要设置一个密钥。
-
设置：session['username'] ＝ 'xxx'
- 删除：session.pop('username', None)
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 |
from flask import Flask, session, redirect, url_for, escape, request
app = Flask(__name__)
@app.route('/')
def index():
if 'username' in session:
return 'Logged in as %s' % escape(session['username'])
return 'You are not logged in'
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'POST':
session['username'] = request.form['username']
return redirect(url_for('index'))
return '''
<form action="" method="post">
<p><input type=text name=username>
<p><input type=submit value=Login>
</form>
'''
@app.route('/logout')
def logout():
# remove the username from the session if it's there
session.pop('username', None)
return redirect(url_for('index'))
# set the secret key. keep this really secret:
app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'
|
4.message
message是一个基于Session实现的用于保存数据的集合，其特点是：使用一次就删除
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 </head>
7 <body>
8 {% with messages = get_flashed_messages() %}
9 {% if messages %}
10 <ul class=flashes>
11 {% for message in messages %}
12 <li>{{ message }}</li>
13 {% endfor %}
14 </ul>
15 {% endif %}
16 {% endwith %}
17 </body>
18 </html>
index.html
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 |
from flask import Flask, flash, redirect, render_template, request
app = Flask(__name__)
app.secret_key = 'some_secret'
@app.route('/')
def index1():
return render_template('index.html')
@app.route('/set')
def index2():
v = request.args.get('p')
flash(v)
return 'ok'
if __name__ == "__main__":
app.run()
|
5.中间件
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
from flask import Flask, flash, redirect, render_template, request
app = Flask(__name__)
app.secret_key = 'some_secret'
@app.route('/')
def index1():
return render_template('index.html')
@app.route('/set')
def index2():
v = request.args.get('p')
flash(v)
return 'ok'
class MiddleWare:
def __init__(self,wsgi_app):
self.wsgi_app = wsgi_app
def __call__(self, *args, **kwargs):
return self.wsgi_app(*args, **kwargs)
if __name__ == "__main__":
app.wsgi_app = MiddleWare(app.wsgi_app)
app.run(port=9999)
|
Flask还有众多其他功能，更多参见：
http://docs.jinkan.org/docs/flask/
http://flask.pocoo.org/
Tornado
Tornado 是 FriendFeed 使用的可扩展的非阻塞式 web 服务器及其相关工具的开源版本。这个 Web 框架看起来有些像web.py 或者 Google 的 webapp，不过为了能有效利用非阻塞式服务器环境，这个 Web 框架还包含了一些相关的有用工具 和优化。
Tornado 和现在的主流 Web 服务器框架（包括大多数 Python 的框架）有着明显的区别：它是非阻塞式服务器，而且速度相当快。得利于其 非阻塞的方式和对 epoll 的运用，Tornado 每秒可以处理数以千计的连接，这意味着对于实时 Web 服务来说，Tornado 是一个理想的 Web 框架。我们开发这个 Web 服务器的主要目的就是为了处理 FriendFeed 的实时功能 ——在 FriendFeed 的应用里每一个活动用户都会保持着一个服务器连接。（关于如何扩容 服务器，以处理数以千计的客户端的连接的问题，请参阅 C10K problem。）
| 1 2 3 |
pip install tornado
源码安装
https://pypi.python.org/packages/source/t/tornado/tornado-4.3.tar.gz
|
一、快速上手
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import tornado.ioloop
import tornado.web
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.write("Hello, world")
application = tornado.web.Application([
(r"/index", MainHandler),
])
if __name__ == "__main__":
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()
|
第一步：执行脚本，监听 8888 端口
第二步：浏览器客户端访问 /index --> http://127.0.0.1:8888/index
第三步：服务器接受请求，并交由对应的类处理该请求
第四步：类接受到请求之后，根据请求方式（post / get / delete ...）的不同调用并执行相应的方法
第五步：方法返回值的字符串内容发送浏览器
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 #!/usr/bin/env python
4 # -*- coding:utf-8 -*-
5
6 import tornado.ioloop
7 import tornado.web
8 from tornado import httpclient
9 from tornado.web import asynchronous
10 from tornado import gen
11
12 import uimodules as md
13 import uimethods as mt
14
15 class MainHandler(tornado.web.RequestHandler):
16 @asynchronous
17 @gen.coroutine
18 def get(self):
19 print 'start get '
20 http = httpclient.AsyncHTTPClient()
21 http.fetch("http://127.0.0.1:8008/post/", self.callback)
22 self.write('end')
23
24 def callback(self, response):
25 print response.body
26
27 settings = {
28 'template_path': 'template',
29 'static_path': 'static',
30 'static_url_prefix': '/static/',
31 'ui_methods': mt,
32 'ui_modules': md,
33 }
34
35 application = tornado.web.Application([
36 (r"/index", MainHandler),
37 ], **settings)
38
39
40 if __name__ == "__main__":
41 application.listen(8009)
42 tornado.ioloop.IOLoop.instance().start()
异步非阻塞实例
二、路由系统
路由系统其实就是 url 和 类 的对应关系，这里不同于其他框架，其他很多框架均是 url 对应 函数，Tornado中每个url对应的是一个类。
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import tornado.ioloop
import tornado.web
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.write("Hello, world")
class StoryHandler(tornado.web.RequestHandler):
def get(self, story_id):
self.write("You requested the story " + story_id)
class BuyHandler(tornado.web.RequestHandler):
def get(self):
self.write("buy.wupeiqi.com/index")
application = tornado.web.Application([
(r"/index", MainHandler),
(r"/story/([0-9]+)", StoryHandler),
])
application.add_handlers('buy.wupeiqi.com$', [
(r'/index',BuyHandler),
])
if __name__ == "__main__":
application.listen(80)
tornado.ioloop.IOLoop.instance().start()
|
三、模板
Tornao中的模板语言和django中类似，模板引擎将模板文件载入内存，然后将数据嵌入其中，最终获取到一个完整的字符串，再将字符串返回给请求者。
Tornado 的模板支持“控制语句”和“表达语句”，控制语句是使用 {% 和 %} 包起来的 例如 {% if len(items) > 2 %}。表达语句是使用 {{ 和 }} 包起来的，例如 {{ items[0] }}。
控制语句和对应的 Python 语句的格式基本完全相同。我们支持 if、for、while 和 try，这些语句逻辑结束的位置需要用 {% end %} 做标记。还通过 extends 和 block 语句实现了模板继承。这些在 template 模块 的代码文档中有着详细的描述。
1 <!DOCTYPE html>
2 <html>
3 <head>
4 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
5 <title>老男孩</title>
6 <link href="{{static_url("css/common.css")}}" rel="stylesheet" />
7 {% block CSS %}{% end %}
8 </head>
9 <body>
10
11 <div class="pg-header">
12
13 </div>
14
15 {% block RenderBody %}{% end %}
16
17 <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script>
18
19 {% block JavaScript %}{% end %}
20 </body>
21 </html>
layout.html
1 {% extends 'layout.html'%}
2 {% block CSS %}
3 <link href="{{static_url("css/index.css")}}" rel="stylesheet" />
4 {% end %}
5
6 {% block RenderBody %}
7 <h1>Index</h1>
8
9 <ul>
10 {% for item in li %}
11 <li>{{item}}</li>
12 {% end %}
13 </ul>
14
15 {% end %}
16
17 {% block JavaScript %}
18
19 {% end %}
index.html
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import tornado.ioloop
import tornado.web
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.render('home/index.html')
settings = {
'template_path': 'template',
}
application = tornado.web.Application([
(r"/index", MainHandler),
], **settings)
if __name__ == "__main__":
application.listen(80)
tornado.ioloop.IOLoop.instance().start()
|
在模板中默认提供了一些函数、字段、类以供模板使用：
escape:tornado.escape.xhtml_escape的別名xhtml_escape:tornado.escape.xhtml_escape的別名url_escape:tornado.escape.url_escape的別名json_encode:tornado.escape.json_encode的別名squeeze:tornado.escape.squeeze的別名linkify:tornado.escape.linkify的別名datetime: Python 的datetime模组handler: 当前的RequestHandler对象request:handler.request的別名current_user:handler.current_user的別名locale:handler.locale的別名_:handler.locale.translate的別名static_url: forhandler.static_url的別名xsrf_form_html:handler.xsrf_form_html的別名
Tornado默认提供的这些功能其实本质上就是 UIMethod 和 UIModule，我们也可以自定义从而实现类似于Django的simple_tag的功能：
1、定义
1 # uimethods.py 2 3 def tab(self): 4 return 'UIMethod'uimethods.py
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 from tornado.web import UIModule
4 from tornado import escape
5
6 class custom(UIModule):
7
8 def render(self, *args, **kwargs):
9 return escape.xhtml_escape('<h1>wupeiqi</h1>')
10 #return escape.xhtml_escape('<h1>wupeiqi</h1>')
uimodules.py
2、注册
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 #!/usr/bin/env python
4 # -*- coding:utf-8 -*-
5
6 import tornado.ioloop
7 import tornado.web
8 from tornado.escape import linkify
9 import uimodules as md
10 import uimethods as mt
11
12 class MainHandler(tornado.web.RequestHandler):
13 def get(self):
14 self.render('index.html')
15
16 settings = {
17 'template_path': 'template',
18 'static_path': 'static',
19 'static_url_prefix': '/static/',
20 'ui_methods': mt,
21 'ui_modules': md,
22 }
23
24 application = tornado.web.Application([
25 (r"/index", MainHandler),
26 ], **settings)
27
28
29 if __name__ == "__main__":
30 application.listen(8009)
31 tornado.ioloop.IOLoop.instance().start()
main.py
3、使用
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 <link href="{{static_url("commons.css")}}" rel="stylesheet" />
7 </head>
8 <body>
9 <h1>hello</h1>
10 {% module custom(123) %}
11 {{ tab() }}
12 </body>
index.html
四、实用功能
1、静态文件
对于静态文件，可以配置静态文件的目录和前段使用时的前缀，并且Tornaodo还支持静态文件缓存。
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3
4 import tornado.ioloop
5 import tornado.web
6
7
8 class MainHandler(tornado.web.RequestHandler):
9 def get(self):
10 self.render('home/index.html')
11
12 settings = {
13 'template_path': 'template',
14 'static_path': 'static',
15 'static_url_prefix': '/static/',
16 }
17
18 application = tornado.web.Application([
19 (r"/index", MainHandler),
20 ], **settings)
21
22
23 if __name__ == "__main__":
24 application.listen(80)
25 tornado.ioloop.IOLoop.instance().start()
main.py
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 <link href="{{static_url("commons.css")}}" rel="stylesheet" />
7 </head>
8 <body>
9 <h1>hello</h1>
10 </body>
11 </html>
index.html
备注：静态文件缓存的实现
1 def get_content_version(cls, abspath): 2 """Returns a version string for the resource at the given path. 3 4 This class method may be overridden by subclasses. The 5 default implementation is a hash of the file's contents. 6 7 .. versionadded:: 3.1 8 """ 9 data = cls.get_content(abspath) 10 hasher = hashlib.md5() 11 if isinstance(data, bytes): 12 hasher.update(data) 13 else: 14 for chunk in data: 15 hasher.update(chunk) 16 return hasher.hexdigest()静态文件缓存源码
2、csrf
Tornado中的夸张请求伪造和Django中的相似，跨站伪造请求(Cross-site request forgery)
1 settings = {
2 "xsrf_cookies": True,
3 }
4 application = tornado.web.Application([
5 (r"/", MainHandler),
6 (r"/login", LoginHandler),
7 ], **settings)
配置
1 <form action="/new_message" method="post">
2 {{ xsrf_form_html() }}
3 <input type="text" name="message"/>
4 <input type="submit" value="Post"/>
5 </form>
普通表单使用
1 function getCookie(name) {
2 var r = document.cookie.match("\\b" + name + "=([^;]*)\\b");
3 return r ? r[1] : undefined;
4 }
5
6 jQuery.postJSON = function(url, args, callback) {
7 args._xsrf = getCookie("_xsrf");
8 $.ajax({url: url, data: $.param(args), dataType: "text", type: "POST",
9 success: function(response) {
10 callback(eval("(" + response + ")"));
11 }});
12 };
Ajax使用
注：Ajax使用时，本质上就是去获取本地的cookie，携带cookie再来发送请求
3、cookie
Tornado中可以对cookie进行操作，并且还可以对cookie进行签名以放置伪造。
a、基本操作
1 class MainHandler(tornado.web.RequestHandler):
2 def get(self):
3 if not self.get_cookie("mycookie"):
4 self.set_cookie("mycookie", "myvalue")
5 self.write("Your cookie was not set yet!")
6 else:
7 self.write("Your cookie was set!")
Code
b、签名
Cookie 很容易被恶意的客户端伪造。加入你想在 cookie 中保存当前登陆用户的 id 之类的信息，你需要对 cookie 作签名以防止伪造。Tornado 通过 set_secure_cookie 和 get_secure_cookie 方法直接支持了这种功能。 要使用这些方法，你需要在创建应用时提供一个密钥，名字为 cookie_secret。 你可以把它作为一个关键词参数传入应用的设置中：
1 class MainHandler(tornado.web.RequestHandler):
2 def get(self):
3 if not self.get_secure_cookie("mycookie"):
4 self.set_secure_cookie("mycookie", "myvalue")
5 self.write("Your cookie was not set yet!")
6 else:
7 self.write("Your cookie was set!")
8
9 application = tornado.web.Application([
10 (r"/", MainHandler),
11 ], cookie_secret="61oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=")
Code
1 def _create_signature_v1(secret, *parts): 2 hash = hmac.new(utf8(secret), digestmod=hashlib.sha1) 3 for part in parts: 4 hash.update(utf8(part)) 5 return utf8(hash.hexdigest()) 6 7 8 def _create_signature_v2(secret, s): 9 hash = hmac.new(utf8(secret), digestmod=hashlib.sha256) 10 hash.update(utf8(s)) 11 return utf8(hash.hexdigest())内部算法
1 def create_signed_value(secret, name, value, version=None, clock=None,
2 key_version=None):
3 if version is None:
4 version = DEFAULT_SIGNED_VALUE_VERSION
5 if clock is None:
6 clock = time.time
7
8 timestamp = utf8(str(int(clock())))
9 value = base64.b64encode(utf8(value))
10 if version == 1:
11 signature = _create_signature_v1(secret, name, value, timestamp)
12 value = b"|".join([value, timestamp, signature])
13 return value
14 elif version == 2:
15 # The v2 format consists of a version number and a series of
16 # length-prefixed fields "%d:%s", the last of which is a
17 # signature, all separated by pipes. All numbers are in
18 # decimal format with no leading zeros. The signature is an
19 # HMAC-SHA256 of the whole string up to that point, including
20 # the final pipe.
21 #
22 # The fields are:
23 # - format version (i.e. 2; no length prefix)
24 # - key version (integer, default is 0)
25 # - timestamp (integer seconds since epoch)
26 # - name (not encoded; assumed to be ~alphanumeric)
27 # - value (base64-encoded)
28 # - signature (hex-encoded; no length prefix)
29 def format_field(s):
30 return utf8("%d:" % len(s)) + utf8(s)
31 to_sign = b"|".join([
32 b"2",
33 format_field(str(key_version or 0)),
34 format_field(timestamp),
35 format_field(name),
36 format_field(value),
37 b''])
38
39 if isinstance(secret, dict):
40 assert key_version is not None, 'Key version must be set when sign key dict is used'
41 assert version >= 2, 'Version must be at least 2 for key version support'
42 secret = secret[key_version]
43
44 signature = _create_signature_v2(secret, to_sign)
45 return to_sign + signature
46 else:
47 raise ValueError("Unsupported version %d" % version)
内部算法-加密
1 def _decode_signed_value_v1(secret, name, value, max_age_days, clock):
2 parts = utf8(value).split(b"|")
3 if len(parts) != 3:
4 return None
5 signature = _create_signature_v1(secret, name, parts[0], parts[1])
6 if not _time_independent_equals(parts[2], signature):
7 gen_log.warning("Invalid cookie signature %r", value)
8 return None
9 timestamp = int(parts[1])
10 if timestamp < clock() - max_age_days * 86400:
11 gen_log.warning("Expired cookie %r", value)
12 return None
13 if timestamp > clock() + 31 * 86400:
14 # _cookie_signature does not hash a delimiter between the
15 # parts of the cookie, so an attacker could transfer trailing
16 # digits from the payload to the timestamp without altering the
17 # signature. For backwards compatibility, sanity-check timestamp
18 # here instead of modifying _cookie_signature.
19 gen_log.warning("Cookie timestamp in future; possible tampering %r",
20 value)
21 return None
22 if parts[1].startswith(b"0"):
23 gen_log.warning("Tampered cookie %r", value)
24 return None
25 try:
26 return base64.b64decode(parts[0])
27 except Exception:
28 return None
29
30
31 def _decode_fields_v2(value):
32 def _consume_field(s):
33 length, _, rest = s.partition(b':')
34 n = int(length)
35 field_value = rest[:n]
36 # In python 3, indexing bytes returns small integers; we must
37 # use a slice to get a byte string as in python 2.
38 if rest[n:n + 1] != b'|':
39 raise ValueError("malformed v2 signed value field")
40 rest = rest[n + 1:]
41 return field_value, rest
42
43 rest = value[2:] # remove version number
44 key_version, rest = _consume_field(rest)
45 timestamp, rest = _consume_field(rest)
46 name_field, rest = _consume_field(rest)
47 value_field, passed_sig = _consume_field(rest)
48 return int(key_version), timestamp, name_field, value_field, passed_sig
49
50
51 def _decode_signed_value_v2(secret, name, value, max_age_days, clock):
52 try:
53 key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value)
54 except ValueError:
55 return None
56 signed_string = value[:-len(passed_sig)]
57
58 if isinstance(secret, dict):
59 try:
60 secret = secret[key_version]
61 except KeyError:
62 return None
63
64 expected_sig = _create_signature_v2(secret, signed_string)
65 if not _time_independent_equals(passed_sig, expected_sig):
66 return None
67 if name_field != utf8(name):
68 return None
69 timestamp = int(timestamp)
70 if timestamp < clock() - max_age_days * 86400:
71 # The signature has expired.
72 return None
73 try:
74 return base64.b64decode(value_field)
75 except Exception:
76 return None
77
78
79 def get_signature_key_version(value):
80 value = utf8(value)
81 version = _get_version(value)
82 if version < 2:
83 return None
84 try:
85 key_version, _, _, _, _ = _decode_fields_v2(value)
86 except ValueError:
87 return None
88
89 return key_version
内部算法-解密
签名Cookie的本质是：
写cookie过程：
- 将值进行base64加密
- 对除值以外的内容进行签名，哈希算法（无法逆向解析）
- 拼接 签名 + 加密值
读cookie过程：
- 读取 签名 + 加密值
- 对签名进行验证
- base64解密，获取值内容
注：许多API验证机制和安全cookie的实现机制相同。
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3
4 import tornado.ioloop
5 import tornado.web
6
7
8 class MainHandler(tornado.web.RequestHandler):
9
10 def get(self):
11 login_user = self.get_secure_cookie("login_user", None)
12 if login_user:
13 self.write(login_user)
14 else:
15 self.redirect('/login')
16
17
18 class LoginHandler(tornado.web.RequestHandler):
19 def get(self):
20 self.current_user()
21
22 self.render('login.html', **{'status': ''})
23
24 def post(self, *args, **kwargs):
25
26 username = self.get_argument('name')
27 password = self.get_argument('pwd')
28 if username == 'wupeiqi' and password == '123':
29 self.set_secure_cookie('login_user', '武沛齐')
30 self.redirect('/')
31 else:
32 self.render('login.html', **{'status': '用户名或密码错误'})
33
34 settings = {
35 'template_path': 'template',
36 'static_path': 'static',
37 'static_url_prefix': '/static/',
38 'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh'
39 }
40
41 application = tornado.web.Application([
42 (r"/index", MainHandler),
43 (r"/login", LoginHandler),
44 ], **settings)
45
46
47 if __name__ == "__main__":
48 application.listen(8888)
49 tornado.ioloop.IOLoop.instance().start()
Demo-基于cookie进行用户验证
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3
4 import tornado.ioloop
5 import tornado.web
6
7 class BaseHandler(tornado.web.RequestHandler):
8
9 def get_current_user(self):
10 return self.get_secure_cookie("login_user")
11
12 class MainHandler(BaseHandler):
13
14 @tornado.web.authenticated
15 def get(self):
16 login_user = self.current_user
17 self.write(login_user)
18
19
20
21 class LoginHandler(tornado.web.RequestHandler):
22 def get(self):
23 self.current_user()
24
25 self.render('login.html', **{'status': ''})
26
27 def post(self, *args, **kwargs):
28
29 username = self.get_argument('name')
30 password = self.get_argument('pwd')
31 if username == 'wupeiqi' and password == '123':
32 self.set_secure_cookie('login_user', '武沛齐')
33 self.redirect('/')
34 else:
35 self.render('login.html', **{'status': '用户名或密码错误'})
36
37 settings = {
38 'template_path': 'template',
39 'static_path': 'static',
40 'static_url_prefix': '/static/',
41 'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
42 'login_url': '/login'
43 }
44
45 application = tornado.web.Application([
46 (r"/index", MainHandler),
47 (r"/login", LoginHandler),
48 ], **settings)
49
50
51 if __name__ == "__main__":
52 application.listen(8888)
53 tornado.ioloop.IOLoop.instance().start()
Demo-Toando内部提供基于cookie进行用户验证
4、Ajax上传文件
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 </head>
7 <body>
8 <input type="file" id="img" />
9 <input type="button" onclick="UploadFile();" />
10 <script>
11 function UploadFile(){
12 var fileObj = document.getElementById("img").files[0];
13
14 var form = new FormData();
15 form.append("k1", "v1");
16 form.append("fff", fileObj);
17
18 var xhr = new XMLHttpRequest();
19 xhr.open("post", '/index', true);
20 xhr.send(form);
21 }
22 </script>
23 </body>
24 </html>
Html
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 #!/usr/bin/env python
4 # -*- coding:utf-8 -*-
5
6 import tornado.ioloop
7 import tornado.web
8
9
10 class MainHandler(tornado.web.RequestHandler):
11 def get(self):
12
13 self.render('index.html')
14
15 def post(self, *args, **kwargs):
16 file_metas = self.request.files["fff"]
17 # print(file_metas)
18 for meta in file_metas:
19 file_name = meta['filename']
20 with open(file_name,'wb') as up:
21 up.write(meta['body'])
22
23 settings = {
24 'template_path': 'template',
25 }
26
27 application = tornado.web.Application([
28 (r"/index", MainHandler),
29 ], **settings)
30
31
32 if __name__ == "__main__":
33 application.listen(8000)
34 tornado.ioloop.IOLoop.instance().start()
Python
1 var fileObj = $("#img")[0].files[0];
2 var form = new FormData();
3 form.append("k1", "v1");
4 form.append("fff", fileObj);
5
6 $.ajax({
7 type:'POST',
8 url: '/index',
9 data: form,
10 processData: false, // tell jQuery not to process the data
11 contentType: false, // tell jQuery not to set contentType
12 success: function(arg){
13 console.log(arg);
14 }
15 })
jQuery Ajax Upload
五、扩展功能
1、自定义Session
a.知识储备
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
class Foo(object):
def __getitem__(self, key):
print '__getitem__',key
def __setitem__(self, key, value):
print '__setitem__',key,value
def __delitem__(self, key):
print '__delitem__',key
obj = Foo()
result = obj['k1']
#obj['k2'] = 'wupeiqi'
#del obj['k1']
|
b.session实现机制
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import tornado.ioloop
import tornado.web
from hashlib import sha1
import os, time
session_container = {}
create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest()
class Session(object):
session_id = "__sessionId__"
def __init__(self, request):
session_value = request.get_cookie(Session.session_id)
if not session_value:
self._id = create_session_id()
else:
self._id = session_value
request.set_cookie(Session.session_id, self._id)
def __getitem__(self, key):
return session_container[self._id][key]
def __setitem__(self, key, value):
if session_container.has_key(self._id):
session_container[self._id][key] = value
else:
session_container[self._id] = {key: value}
def __delitem__(self, key):
del session_container[self._id][key]
class BaseHandler(tornado.web.RequestHandler):
def initialize(self):
# my_session['k1']访问 __getitem__ 方法
self.my_session = Session(self)
class MainHandler(BaseHandler):
def get(self):
print self.my_session['c_user']
print self.my_session['c_card']
self.write('index')
class LoginHandler(BaseHandler):
def get(self):
self.render('login.html', **{'status': ''})
def post(self, *args, **kwargs):
username = self.get_argument('name')
password = self.get_argument('pwd')
if username == 'wupeiqi' and password == '123':
self.my_session['c_user'] = 'wupeiqi'
self.my_session['c_card'] = '12312312309823012'
self.redirect('/index')
else:
self.render('login.html', **{'status': '用户名或密码错误'})
settings = {
'template_path': 'template',
'static_path': 'static',
'static_url_prefix': '/static/',
'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
'login_url': '/login'
}
application = tornado.web.Application([
(r"/index", MainHandler),
(r"/login", LoginHandler),
], **settings)
if __name__ == "__main__":
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()
|
c. Session框架
1 #!/usr/bin/env python
2 #coding:utf-8
3
4 import sys
5 import math
6 from bisect import bisect
7
8
9 if sys.version_info >= (2, 5):
10 import hashlib
11 md5_constructor = hashlib.md5
12 else:
13 import md5
14 md5_constructor = md5.new
15
16
17 class HashRing(object):
18 """一致性哈希"""
19
20 def __init__(self,nodes):
21 '''初始化
22 nodes : 初始化的节点，其中包含节点已经节点对应的权重
23 默认每一个节点有32个虚拟节点
24 对于权重，通过多创建虚拟节点来实现
25 如：nodes = [
26 {'host':'127.0.0.1:8000','weight':1},
27 {'host':'127.0.0.1:8001','weight':2},
28 {'host':'127.0.0.1:8002','weight':1},
29 ]
30 '''
31
32 self.ring = dict()
33 self._sorted_keys = []
34
35 self.total_weight = 0
36
37 self.__generate_circle(nodes)
38
39
40
41 def __generate_circle(self,nodes):
42 for node_info in nodes:
43 self.total_weight += node_info.get('weight',1)
44
45 for node_info in nodes:
46 weight = node_info.get('weight',1)
47 node = node_info.get('host',None)
48
49 virtual_node_count = math.floor((32*len(nodes)*weight) / self.total_weight)
50 for i in xrange(0,int(virtual_node_count)):
51 key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
52 if self._sorted_keys.__contains__(key):
53 raise Exception('该节点已经存在.')
54 self.ring[key] = node
55 self._sorted_keys.append(key)
56
57 def add_node(self,node):
58 ''' 新建节点
59 node : 要添加的节点，格式为：{'host':'127.0.0.1:8002','weight':1}，其中第一个元素表示节点，第二个元素表示该节点的权重。
60 '''
61 node = node.get('host',None)
62 if not node:
63 raise Exception('节点的地址不能为空.')
64
65 weight = node.get('weight',1)
66
67 self.total_weight += weight
68 nodes_count = len(self._sorted_keys) + 1
69
70 virtual_node_count = math.floor((32 * nodes_count * weight) / self.total_weight)
71 for i in xrange(0,int(virtual_node_count)):
72 key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
73 if self._sorted_keys.__contains__(key):
74 raise Exception('该节点已经存在.')
75 self.ring[key] = node
76 self._sorted_keys.append(key)
77
78 def remove_node(self,node):
79 ''' 移除节点
80 node : 要移除的节点 '127.0.0.1:8000'
81 '''
82 for key,value in self.ring.items():
83 if value == node:
84 del self.ring[key]
85 self._sorted_keys.remove(key)
86
87 def get_node(self,string_key):
88 '''获取 string_key 所在的节点'''
89 pos = self.get_node_pos(string_key)
90 if pos is None:
91 return None
92 return self.ring[ self._sorted_keys[pos]].split(':')
93
94 def get_node_pos(self,string_key):
95 '''获取 string_key 所在的节点的索引'''
96 if not self.ring:
97 return None
98
99 key = self.gen_key_thirty_two(string_key)
100 nodes = self._sorted_keys
101 pos = bisect(nodes, key)
102 return pos
103
104 def gen_key_thirty_two(self, key):
105
106 m = md5_constructor()
107 m.update(key)
108 return long(m.hexdigest(), 16)
109
110 def gen_key_sixteen(self,key):
111
112 b_key = self.__hash_digest(key)
113 return self.__hash_val(b_key, lambda x: x)
114
115 def __hash_val(self, b_key, entry_fn):
116 return (( b_key[entry_fn(3)] << 24)|(b_key[entry_fn(2)] << 16)|(b_key[entry_fn(1)] << 8)| b_key[entry_fn(0)] )
117
118 def __hash_digest(self, key):
119 m = md5_constructor()
120 m.update(key)
121 return map(ord, m.digest())
122
123
124 """
125 nodes = [
126 {'host':'127.0.0.1:8000','weight':1},
127 {'host':'127.0.0.1:8001','weight':2},
128 {'host':'127.0.0.1:8002','weight':1},
129 ]
130
131 ring = HashRing(nodes)
132 result = ring.get_node('98708798709870987098709879087')
133 print result
134
135 """
一致性哈希
1 from hashlib import sha1
2 import os, time
3
4
5 create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest()
6
7
8 class Session(object):
9
10 session_id = "__sessionId__"
11
12 def __init__(self, request):
13 session_value = request.get_cookie(Session.session_id)
14 if not session_value:
15 self._id = create_session_id()
16 else:
17 self._id = session_value
18 request.set_cookie(Session.session_id, self._id)
19
20 def __getitem__(self, key):
21 # 根据 self._id ，在一致性哈西中找到其对应的服务器IP
22 # 找到相对应的redis服务器，如： r = redis.StrictRedis(host='localhost', port=6379, db=0)
23 # 使用python redis api 链接
24 # 获取数据，即：
25 # return self._redis.hget(self._id, name)
26
27 def __setitem__(self, key, value):
28 # 根据 self._id ，在一致性哈西中找到其对应的服务器IP
29 # 使用python redis api 链接
30 # 设置session
31 # self._redis.hset(self._id, name, value)
32
33
34 def __delitem__(self, key):
35 # 根据 self._id 找到相对应的redis服务器
36 # 使用python redis api 链接
37 # 删除，即：
38 return self._redis.hdel(self._id, name)
Session
2、自定义模型版定
模型绑定有两个主要功能：
- 自动生成html表单
- 用户输入验证
在之前学习的Django中为程序员提供了非常便捷的模型绑定功能，但是在Tornado中，一切需要自己动手！！！
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 <link href="{{static_url("commons.css")}}" rel="stylesheet" />
7 </head>
8 <body>
9 <h1>hello</h1>
10 <form action="/index" method="post">
11
12 <p>hostname: <input type="text" name="host" /> </p>
13 <p>ip: <input type="text" name="ip" /> </p>
14 <p>port: <input type="text" name="port" /> </p>
15 <p>phone: <input type="text" name="phone" /> </p>
16 <input type="submit" />
17 </form>
18 </body>
19 </html>
html
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 |
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import tornado.ioloop
import tornado.web
from hashlib import sha1
import os, time
import re
class MainForm(object):
def __init__(self):
self.host = "(.*)"
self.ip = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"
self.port = '(\d+)'
self.phone = '^1[3|4|5|8][0-9]\d{8}$'
def check_valid(self, request):
form_dict = self.__dict__
for key, regular in form_dict.items():
post_value = request.get_argument(key)
# 让提交的数据 和 定义的正则表达式进行匹配
ret = re.match(regular, post_value)
print key,ret,post_value
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.render('index.html')
def post(self, *args, **kwargs):
obj = MainForm()
result = obj.check_valid(self)
self.write('ok')
settings = {
'template_path': 'template',
'static_path': 'static',
'static_url_prefix': '/static/',
'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
'login_url': '/login'
}
application = tornado.web.Application([
(r"/index", MainHandler),
], **settings)
if __name__ == "__main__":
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()
|
由于请求的验证时，需要考虑是否可以为空以及正则表达式的复用，所以：
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3
4 import tornado.ioloop
5 import tornado.web
6 import re
7
8
9 class Field(object):
10
11 def __init__(self, error_msg_dict, required):
12 self.id_valid = False
13 self.value = None
14 self.error = None
15 self.name = None
16 self.error_msg = error_msg_dict
17 self.required = required
18
19 def match(self, name, value):
20 self.name = name
21
22 if not self.required:
23 self.id_valid = True
24 self.value = value
25 else:
26 if not value:
27 if self.error_msg.get('required', None):
28 self.error = self.error_msg['required']
29 else:
30 self.error = "%s is required" % name
31 else:
32 ret = re.match(self.REGULAR, value)
33 if ret:
34 self.id_valid = True
35 self.value = ret.group()
36 else:
37 if self.error_msg.get('valid', None):
38 self.error = self.error_msg['valid']
39 else:
40 self.error = "%s is invalid" % name
41
42
43 class IPField(Field):
44 REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"
45
46 def __init__(self, error_msg_dict=None, required=True):
47
48 error_msg = {} # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
49 if error_msg_dict:
50 error_msg.update(error_msg_dict)
51
52 super(IPField, self).__init__(error_msg_dict=error_msg, required=required)
53
54
55 class IntegerField(Field):
56 REGULAR = "^\d+$"
57
58 def __init__(self, error_msg_dict=None, required=True):
59 error_msg = {'required': '数字不能为空', 'valid': '数字格式错误'}
60 if error_msg_dict:
61 error_msg.update(error_msg_dict)
62
63 super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required)
64
65
66 class CheckBoxField(Field):
67
68 def __init__(self, error_msg_dict=None, required=True):
69 error_msg = {} # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
70 if error_msg_dict:
71 error_msg.update(error_msg_dict)
72
73 super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required)
74
75 def match(self, name, value):
76 self.name = name
77
78 if not self.required:
79 self.id_valid = True
80 self.value = value
81 else:
82 if not value:
83 if self.error_msg.get('required', None):
84 self.error = self.error_msg['required']
85 else:
86 self.error = "%s is required" % name
87 else:
88 if isinstance(name, list):
89 self.id_valid = True
90 self.value = value
91 else:
92 if self.error_msg.get('valid', None):
93 self.error = self.error_msg['valid']
94 else:
95 self.error = "%s is invalid" % name
96
97
98 class FileField(Field):
99 REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$"
100
101 def __init__(self, error_msg_dict=None, required=True):
102 error_msg = {} # {'required': '数字不能为空', 'valid': '数字格式错误'}
103 if error_msg_dict:
104 error_msg.update(error_msg_dict)
105
106 super(FileField, self).__init__(error_msg_dict=error_msg, required=required)
107
108 def match(self, name, value):
109 self.name = name
110 self.value = []
111 if not self.required:
112 self.id_valid = True
113 self.value = value
114 else:
115 if not value:
116 if self.error_msg.get('required', None):
117 self.error = self.error_msg['required']
118 else:
119 self.error = "%s is required" % name
120 else:
121 m = re.compile(self.REGULAR)
122 if isinstance(value, list):
123 for file_name in value:
124 r = m.match(file_name)
125 if r:
126 self.value.append(r.group())
127 self.id_valid = True
128 else:
129 self.id_valid = False
130 if self.error_msg.get('valid', None):
131 self.error = self.error_msg['valid']
132 else:
133 self.error = "%s is invalid" % name
134 break
135 else:
136 if self.error_msg.get('valid', None):
137 self.error = self.error_msg['valid']
138 else:
139 self.error = "%s is invalid" % name
140
141 def save(self, request, upload_path=""):
142
143 file_metas = request.files[self.name]
144 for meta in file_metas:
145 file_name = meta['filename']
146 with open(file_name,'wb') as up:
147 up.write(meta['body'])
148
149
150 class Form(object):
151
152 def __init__(self):
153 self.value_dict = {}
154 self.error_dict = {}
155 self.valid_status = True
156
157 def validate(self, request, depth=10, pre_key=""):
158
159 self.initialize()
160 self.__valid(self, request, depth, pre_key)
161
162 def initialize(self):
163 pass
164
165 def __valid(self, form_obj, request, depth, pre_key):
166 """
167 验证用户表单请求的数据
168 :param form_obj: Form对象（Form派生类的对象）
169 :param request: Http请求上下文（用于从请求中获取用户提交的值）
170 :param depth: 对Form内容的深度的支持
171 :param pre_key: Html中name属性值的前缀（多层Form时，内部递归时设置，无需理会）
172 :return: 是否验证通过，True：验证成功；False：验证失败
173 """
174
175 depth -= 1
176 if depth < 0:
177 return None
178 form_field_dict = form_obj.__dict__
179 for key, field_obj in form_field_dict.items():
180 print key,field_obj
181 if isinstance(field_obj, Form) or isinstance(field_obj, Field):
182 if isinstance(field_obj, Form):
183 # 获取以key开头的所有的值，以参数的形式传至
184 self.__valid(field_obj, request, depth, key)
185 continue
186 if pre_key:
187 key = "%s.%s" % (pre_key, key)
188
189 if isinstance(field_obj, CheckBoxField):
190 post_value = request.get_arguments(key, None)
191 elif isinstance(field_obj, FileField):
192 post_value = []
193 file_list = request.request.files.get(key, None)
194 for file_item in file_list:
195 post_value.append(file_item['filename'])
196 else:
197 post_value = request.get_argument(key, None)
198
199 print post_value
200 # 让提交的数据 和 定义的正则表达式进行匹配
201 field_obj.match(key, post_value)
202 if field_obj.id_valid:
203 self.value_dict[key] = field_obj.value
204 else:
205 self.error_dict[key] = field_obj.error
206 self.valid_status = False
207
208
209 class ListForm(object):
210 def __init__(self, form_type):
211 self.form_type = form_type
212 self.valid_status = True
213 self.value_dict = {}
214 self.error_dict = {}
215
216 def validate(self, request):
217 name_list = request.request.arguments.keys() + request.request.files.keys()
218 index = 0
219 flag = False
220 while True:
221 pre_key = "[%d]" % index
222 for name in name_list:
223 if name.startswith(pre_key):
224 flag = True
225 break
226 if flag:
227 form_obj = self.form_type()
228 form_obj.validate(request, depth=10, pre_key="[%d]" % index)
229 if form_obj.valid_status:
230 self.value_dict[index] = form_obj.value_dict
231 else:
232 self.error_dict[index] = form_obj.error_dict
233 self.valid_status = False
234 else:
235 break
236
237 index += 1
238 flag = False
239
240
241 class MainForm(Form):
242
243 def __init__(self):
244 # self.ip = IPField(required=True)
245 # self.port = IntegerField(required=True)
246 # self.new_ip = IPField(required=True)
247 # self.second = SecondForm()
248 self.fff = FileField(required=True)
249 super(MainForm, self).__init__()
250
251 #
252 # class SecondForm(Form):
253 #
254 # def __init__(self):
255 # self.ip = IPField(required=True)
256 # self.new_ip = IPField(required=True)
257 #
258 # super(SecondForm, self).__init__()
259
260
261 class MainHandler(tornado.web.RequestHandler):
262 def get(self):
263 self.render('index.html')
264 def post(self, *args, **kwargs):
265 # for i in dir(self.request):
266 # print i
267 # print self.request.arguments
268 # print self.request.files
269 # print self.request.query
270 # name_list = self.request.arguments.keys() + self.request.files.keys()
271 # print name_list
272
273 # list_form = ListForm(MainForm)
274 # list_form.validate(self)
275 #
276 # print list_form.valid_status
277 # print list_form.value_dict
278 # print list_form.error_dict
279
280 # obj = MainForm()
281 # obj.validate(self)
282 #
283 # print "验证结果：", obj.valid_status
284 # print "符合验证结果：", obj.value_dict
285 # print "错误信息:"
286 # for key, item in obj.error_dict.items():
287 # print key,item
288 # print self.get_arguments('favor'),type(self.get_arguments('favor'))
289 # print self.get_argument('favor'),type(self.get_argument('favor'))
290 # print type(self.get_argument('fff')),self.get_argument('fff')
291 # print self.request.files
292 # obj = MainForm()
293 # obj.validate(self)
294 # print obj.valid_status
295 # print obj.value_dict
296 # print obj.error_dict
297 # print self.request,type(self.request)
298 # obj.fff.save(self.request)
299 # from tornado.httputil import HTTPServerRequest
300 # name_list = self.request.arguments.keys() + self.request.files.keys()
301 # print name_list
302 # print self.request.files,type(self.request.files)
303 # print len(self.request.files.get('fff'))
304
305 # obj = MainForm()
306 # obj.validate(self)
307 # print obj.valid_status
308 # print obj.value_dict
309 # print obj.error_dict
310 # obj.fff.save(self.request)
311 self.write('ok')
312
313
314
315 settings = {
316 'template_path': 'template',
317 'static_path': 'static',
318 'static_url_prefix': '/static/',
319 'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
320 'login_url': '/login'
321 }
322
323 application = tornado.web.Application([
324 (r"/index", MainHandler),
325 ], **settings)
326
327
328 if __name__ == "__main__":
329 application.listen(8888)
330 tornado.ioloop.IOLoop.instance().start()
Form验证框架
这篇关于Python之路【第十八篇】：Web框架们的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！
您可能喜欢
-
使用python部署一个usdt合约，部署自己的usdt稳定币12-23
-
Python编程入门指南12-20
-
Python编程基础与进阶12-20
-
Python基础编程教程12-19
-
python 文件的后缀名是什么 怎么运行一个python文件？-icode9专业技术文章分享12-19
-
使用python 把docx转为pdf文件有哪些方法？-icode9专业技术文章分享12-19
-
python怎么更换换pip的源镜像？-icode9专业技术文章分享12-19
-
Python资料：新手入门的全面指南12-19
-
Python股票自动化交易实战入门教程12-19
-
Python股票自动化交易入门教程12-19
-
Python量化入门教程：轻松掌握量化交易基础知识12-18
-
Python股票自动化交易入门：初学者指南12-18
-
Python量化交易：新手入门教程12-18
-
Python入门：从零开始学习Python编程12-18
-
Python入门：轻松掌握Python编程基础12-18
栏目导航
