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畅游Python 二十一：Web框架 - Tornado

發(fā)布時(shí)間：2024/3/12 python 51 豆豆

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Tornado?是?FriendFeed?使用的可擴(kuò)展的非阻塞式 web 服務(wù)器及其相關(guān)工具的開(kāi)源版本。這個(gè) Web 框架看起來(lái)有些像web.py?或者?Google 的 webapp，不過(guò)為了能有效利用非阻塞式服務(wù)器環(huán)境，這個(gè) Web 框架還包含了一些相關(guān)的有用工具和優(yōu)化。

Tornado 和現(xiàn)在的主流 Web 服務(wù)器框架（包括大多數(shù) Python 的框架）有著明顯的區(qū)別：它是非阻塞式服務(wù)器，而且速度相當(dāng)快。得利于其非阻塞的方式和對(duì)?epoll?的運(yùn)用，Tornado 每秒可以處理數(shù)以千計(jì)的連接，這意味著對(duì)于實(shí)時(shí) Web 服務(wù)來(lái)說(shuō)，Tornado 是一個(gè)理想的 Web 框架。我們開(kāi)發(fā)這個(gè) Web 服務(wù)器的主要目的就是為了處理 FriendFeed 的實(shí)時(shí)功能 ——在 FriendFeed 的應(yīng)用里每一個(gè)活動(dòng)用戶(hù)都會(huì)保持著一個(gè)服務(wù)器連接。（關(guān)于如何擴(kuò)容服務(wù)器，以處理數(shù)以千計(jì)的客戶(hù)端的連接的問(wèn)題，請(qǐng)參閱?C10K problem。）

下載安裝：

pip3 install tornado源碼安裝 https://pypi.python.org/packages/source/t/tornado/tornado-4.3.tar.gz

Tornado框架使用

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.webclass 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()

執(zhí)行過(guò)程：

第一步：執(zhí)行腳本，監(jiān)聽(tīng) 8888 端口
第二步：瀏覽器客戶(hù)端訪(fǎng)問(wèn) /index ?--> ?http://127.0.0.1:8888/index
第三步：服務(wù)器接受請(qǐng)求，并交由對(duì)應(yīng)的類(lèi)處理該請(qǐng)求
第四步：類(lèi)接受到請(qǐng)求之后，根據(jù)請(qǐng)求方式（post / get / delete ...）的不同調(diào)用并執(zhí)行相應(yīng)的方法
第五步：方法返回值的字符串內(nèi)容發(fā)送瀏覽器

異步非阻塞代碼示例：

#!/usr/bin/env python # -*- coding:utf-8 -*- #!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.web from tornado import httpclient from tornado.web import asynchronous from tornado import genimport uimodules as md import uimethods as mtclass MainHandler(tornado.web.RequestHandler):@asynchronous@gen.coroutinedef get(self):print 'start get 'http = httpclient.AsyncHTTPClient()http.fetch("http://127.0.0.1:8008/post/", self.callback)self.write('end')def callback(self, response):print response.bodysettings = {'template_path': 'template','static_path': 'static','static_url_prefix': '/static/','ui_methods': mt,'ui_modules': md, }application = tornado.web.Application([(r"/index", MainHandler), ], **settings)if __name__ == "__main__":application.listen(8009)tornado.ioloop.IOLoop.instance().start()

二、路由系統(tǒng)

路由系統(tǒng)其實(shí)就是 url 和類(lèi) 的對(duì)應(yīng)關(guān)系，這里不同于其他框架，其他很多框架均是 url 對(duì)應(yīng) 函數(shù)，Tornado中每個(gè)url對(duì)應(yīng)的是一個(gè)類(lèi)。

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.webclass 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()

Tornado中原生支持二級(jí)域名的路由，如：

模板引擎

Tornao中的模板語(yǔ)言和django中類(lèi)似，模板引擎將模板文件載入內(nèi)存，然后將數(shù)據(jù)嵌入其中，最終獲取到一個(gè)完整的字符串，再將字符串返回給請(qǐng)求者。

Tornado 的模板支持“控制語(yǔ)句”和“表達(dá)語(yǔ)句”，控制語(yǔ)句是使用?{%?和?%}?包起來(lái)的例如?{% if len(items) > 2 %}。表達(dá)語(yǔ)句是使用?{{?和?}}?包起來(lái)的，例如?{{ items[0] }}。

控制語(yǔ)句和對(duì)應(yīng)的 Python 語(yǔ)句的格式基本完全相同。我們支持?if、for、while?和?try，這些語(yǔ)句邏輯結(jié)束的位置需要用?{% end %}?做標(biāo)記。還通過(guò)?extends?和?block?語(yǔ)句實(shí)現(xiàn)了模板繼承。這些在?template?模塊?的代碼文檔中有著詳細(xì)的描述。

注：在使用模板前需要在setting中設(shè)置模板路徑："template_path" : "tpl"

1、基本使用

app.py代碼：

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.webclass MainHandler(tornado.web.RequestHandler):def get(self):self.render("index.html", list_info = [11,22,33])application = tornado.web.Application([(r"/index", MainHandler), ])if __name__ == "__main__":application.listen(8888)tornado.ioloop.IOLoop.instance().start()

‘index.html’ 代碼：

<!DOCTYPE html> <html> <head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><title>老男孩</title><link href="{{static_url("css/common.css")}}" rel="stylesheet" /> </head> <body><div><ul>{% for item in list_info %}<li>{{item}}</li>{% end %}</ul></div><script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script></body> </html>

其他方法代碼：

在模板中默認(rèn)提供了一些函數(shù)、字段、類(lèi)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 模組 handler: 當(dāng)前的 RequestHandler 對(duì)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: for handler.static_url 的別名 xsrf_form_html: handler.xsrf_form_html 的別名

2、母版

2.1?layout.html

<!DOCTYPE html> <html> <head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><title>老男孩</title><link href="{{static_url("css/common.css")}}" rel="stylesheet" />{% block CSS %}{% end %} </head> <body><div class="pg-header"></div>{% block RenderBody %}{% end %}<script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script>{% block JavaScript %}{% end %} </body> </html>

2.2?index.html

{% extends 'layout.html'%} {% block CSS %}<link href="{{static_url("css/index.css")}}" rel="stylesheet" /> {% end %}{% block RenderBody %}<h1>Index</h1><ul>{% for item in li %}<li>{{item}}</li>{% end %}</ul>{% end %}{% block JavaScript %}{% end %}

3、導(dǎo)入

3.1?header.html

3.2?index.html

<!DOCTYPE html> <html> <head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><title>老男孩</title><link href="{{static_url("css/common.css")}}" rel="stylesheet" /> </head> <body><div class="pg-header">{% include 'header.html' %}</div><script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script></body> </html>

4、自定義UIMethod以UIModule

4.1 定義

4.1.1?uimethods.py

# uimethods.pydef tab(self):return 'UIMethod'

4.1.2?uimodules.py

#!/usr/bin/env python # -*- coding:utf-8 -*- from tornado.web import UIModule from tornado import escapeclass custom(UIModule):def render(self, *args, **kwargs):return escape.xhtml_escape('<h1>wupeiqi</h1>')#return escape.xhtml_escape('<h1>wupeiqi</h1>')

4.2?注冊(cè)

#!/usr/bin/env python # -*- coding:utf-8 -*- #!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.web from tornado.escape import linkify import uimodules as md import uimethods as mtclass MainHandler(tornado.web.RequestHandler):def get(self):self.render('index.html')settings = {'template_path': 'template','static_path': 'static','static_url_prefix': '/static/','ui_methods': mt,'ui_modules': md, }application = tornado.web.Application([(r"/index", MainHandler), ], **settings)if __name__ == "__main__":application.listen(8009)tornado.ioloop.IOLoop.instance().start()

4.3 使用

四、靜態(tài)文件

對(duì)于靜態(tài)文件，可以配置靜態(tài)文件的目錄和前段使用時(shí)的前綴，并且Tornaodo還支持靜態(tài)文件緩存。

1.?app.py

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.webclass MainHandler(tornado.web.RequestHandler):def get(self):self.render('home/index.html')settings = {'template_path': 'template','static_path': 'static','static_url_prefix': '/static/', }application = tornado.web.Application([(r"/index", MainHandler), ], **settings)if __name__ == "__main__":application.listen(80)tornado.ioloop.IOLoop.instance().start()

2.?index.html

<!DOCTYPE html> <html> <head lang="en"><meta charset="UTF-8"><title></title><link href="{{static_url("commons.css")}}" rel="stylesheet" /> </head> <body><h1>hello</h1> </body> </html>

3. 靜態(tài)文件緩存的實(shí)現(xiàn)

def get_content_version(cls, abspath):"""Returns a version string for the resource at the given path.This class method may be overridden by subclasses. Thedefault implementation is a hash of the file's contents... versionadded:: 3.1"""data = cls.get_content(abspath)hasher = hashlib.md5()if isinstance(data, bytes):hasher.update(data)else:for chunk in data:hasher.update(chunk)return hasher.hexdigest()

五、cookie

Tornado中可以對(duì)cookie進(jìn)行操作，并且還可以對(duì)cookie進(jìn)行簽名以放置偽造。

1、基本操作

class MainHandler(tornado.web.RequestHandler):def get(self):if not self.get_cookie("mycookie"):self.set_cookie("mycookie", "myvalue")self.write("Your cookie was not set yet!")else:self.write("Your cookie was set!")

2、加密cookie（簽名）

Cookie 很容易被惡意的客戶(hù)端偽造。加入你想在 cookie 中保存當(dāng)前登陸用戶(hù)的 id 之類(lèi)的信息，你需要對(duì) cookie 作簽名以防止偽造。Tornado 通過(guò) set_secure_cookie 和 get_secure_cookie 方法直接支持了這種功能。要使用這些方法，你需要在創(chuàng)建應(yīng)用時(shí)提供一個(gè)密鑰，名字為 cookie_secret。你可以把它作為一個(gè)關(guān)鍵詞參數(shù)傳入應(yīng)用的設(shè)置中：

class MainHandler(tornado.web.RequestHandler):def get(self):if not self.get_secure_cookie("mycookie"):self.set_secure_cookie("mycookie", "myvalue")self.write("Your cookie was not set yet!")else:self.write("Your cookie was set!")application = tornado.web.Application([(r"/", MainHandler), ], cookie_secret="61oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=")

內(nèi)部算法：

def _create_signature_v1(secret, *parts):hash = hmac.new(utf8(secret), digestmod=hashlib.sha1)for part in parts:hash.update(utf8(part))return utf8(hash.hexdigest())# 加密 def _create_signature_v2(secret, s):hash = hmac.new(utf8(secret), digestmod=hashlib.sha256)hash.update(utf8(s))return utf8(hash.hexdigest())def create_signed_value(secret, name, value, version=None, clock=None,key_version=None):if version is None:version = DEFAULT_SIGNED_VALUE_VERSIONif clock is None:clock = time.timetimestamp = utf8(str(int(clock())))value = base64.b64encode(utf8(value))if version == 1:signature = _create_signature_v1(secret, name, value, timestamp)value = b"|".join([value, timestamp, signature])return valueelif version == 2:# The v2 format consists of a version number and a series of# length-prefixed fields "%d:%s", the last of which is a# signature, all separated by pipes. All numbers are in# decimal format with no leading zeros. The signature is an# HMAC-SHA256 of the whole string up to that point, including# the final pipe.## The fields are:# - format version (i.e. 2; no length prefix)# - key version (integer, default is 0)# - timestamp (integer seconds since epoch)# - name (not encoded; assumed to be ~alphanumeric)# - value (base64-encoded)# - signature (hex-encoded; no length prefix)def format_field(s):return utf8("%d:" % len(s)) + utf8(s)to_sign = b"|".join([b"2",format_field(str(key_version or 0)),format_field(timestamp),format_field(name),format_field(value),b''])if isinstance(secret, dict):assert key_version is not None, 'Key version must be set when sign key dict is used'assert version >= 2, 'Version must be at least 2 for key version support'secret = secret[key_version]signature = _create_signature_v2(secret, to_sign)return to_sign + signatureelse:raise ValueError("Unsupported version %d" % version)# 解密 def _decode_signed_value_v1(secret, name, value, max_age_days, clock):parts = utf8(value).split(b"|")if len(parts) != 3:return Nonesignature = _create_signature_v1(secret, name, parts[0], parts[1])if not _time_independent_equals(parts[2], signature):gen_log.warning("Invalid cookie signature %r", value)return Nonetimestamp = int(parts[1])if timestamp < clock() - max_age_days * 86400:gen_log.warning("Expired cookie %r", value)return Noneif timestamp > clock() + 31 * 86400:# _cookie_signature does not hash a delimiter between the# parts of the cookie, so an attacker could transfer trailing# digits from the payload to the timestamp without altering the# signature. For backwards compatibility, sanity-check timestamp# here instead of modifying _cookie_signature.gen_log.warning("Cookie timestamp in future; possible tampering %r",value)return Noneif parts[1].startswith(b"0"):gen_log.warning("Tampered cookie %r", value)return Nonetry:return base64.b64decode(parts[0])except Exception:return Nonedef _decode_fields_v2(value):def _consume_field(s):length, _, rest = s.partition(b':')n = int(length)field_value = rest[:n]# In python 3, indexing bytes returns small integers; we must# use a slice to get a byte string as in python 2.if rest[n:n + 1] != b'|':raise ValueError("malformed v2 signed value field")rest = rest[n + 1:]return field_value, restrest = value[2:] # remove version numberkey_version, rest = _consume_field(rest)timestamp, rest = _consume_field(rest)name_field, rest = _consume_field(rest)value_field, passed_sig = _consume_field(rest)return int(key_version), timestamp, name_field, value_field, passed_sigdef _decode_signed_value_v2(secret, name, value, max_age_days, clock):try:key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value)except ValueError:return Nonesigned_string = value[:-len(passed_sig)]if isinstance(secret, dict):try:secret = secret[key_version]except KeyError:return Noneexpected_sig = _create_signature_v2(secret, signed_string)if not _time_independent_equals(passed_sig, expected_sig):return Noneif name_field != utf8(name):return Nonetimestamp = int(timestamp)if timestamp < clock() - max_age_days * 86400:# The signature has expired.return Nonetry:return base64.b64decode(value_field)except Exception:return Nonedef get_signature_key_version(value):value = utf8(value)version = _get_version(value)if version < 2:return Nonetry:key_version, _, _, _, _ = _decode_fields_v2(value)except ValueError:return Nonereturn key_version

簽名Cookie的本質(zhì)是：

寫(xiě)cookie過(guò)程：

將值進(jìn)行base64加密
對(duì)除值以外的內(nèi)容進(jìn)行簽名，哈希算法（無(wú)法逆向解析）
拼接簽名 + 加密值

讀cookie過(guò)程：

讀取簽名 + 加密值
對(duì)簽名進(jìn)行驗(yàn)證
base64解密，獲取值內(nèi)容

注：許多API驗(yàn)證機(jī)制和安全cookie的實(shí)現(xiàn)機(jī)制相同。

基于Cookie實(shí)現(xiàn)用戶(hù)驗(yàn)證代碼實(shí)例：

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.webclass MainHandler(tornado.web.RequestHandler):def get(self):login_user = self.get_secure_cookie("login_user", None)if login_user:self.write(login_user)else:self.redirect('/login')class LoginHandler(tornado.web.RequestHandler):def get(self):self.current_user()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.set_secure_cookie('login_user', '武沛齊')self.redirect('/')else:self.render('login.html', **{'status': '用戶(hù)名或密碼錯(cuò)誤'})settings = {'template_path': 'template','static_path': 'static','static_url_prefix': '/static/','cookie_secret': 'aiuasdhflashjdfoiuashdfiuh' }application = tornado.web.Application([(r"/index", MainHandler),(r"/login", LoginHandler), ], **settings)if __name__ == "__main__":application.listen(8888)tornado.ioloop.IOLoop.instance().start()

基于簽名Cookie實(shí)現(xiàn)用戶(hù)驗(yàn)證代碼實(shí)例：

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.webclass BaseHandler(tornado.web.RequestHandler):def get_current_user(self):return self.get_secure_cookie("login_user")class MainHandler(BaseHandler):@tornado.web.authenticateddef get(self):login_user = self.current_userself.write(login_user)class LoginHandler(tornado.web.RequestHandler):def get(self):self.current_user()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.set_secure_cookie('login_user', '武沛齊')self.redirect('/')else:self.render('login.html', **{'status': '用戶(hù)名或密碼錯(cuò)誤'})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()

3、JavaScript操作Cookie

由于Cookie保存在瀏覽器端，所以在瀏覽器端也可以使用JavaScript來(lái)操作Cookie。

/* 設(shè)置cookie，指定秒數(shù)過(guò)期*/ function setCookie(name,value,expires){var temp = [];var current_date = new Date();current_date.setSeconds(current_date.getSeconds() + 5);document.cookie = name + "= "+ value +";expires=" + current_date.toUTCString(); }

對(duì)于參數(shù)：

domain ? 指定域名下的cookie
path ? ? ? 域名下指定url中的cookie
secure ? ?https使用

注：jQuery中也有指定的插件 jQuery Cookie 專(zhuān)門(mén)用于操作cookie，猛擊這里

六、CSRF

Tornado中的夸張請(qǐng)求偽造和Django中的相似，跨站偽造請(qǐng)求(Cross-site request forgery)

配置：

settings = {"xsrf_cookies": True, } application = tornado.web.Application([(r"/", MainHandler),(r"/login", LoginHandler), ], **settings)

使用普通表單：

使用AJAX：

注：Ajax使用時(shí)，本質(zhì)上就是去獲取本地的cookie，攜帶cookie再來(lái)發(fā)送請(qǐng)求

七、上傳文件

1、Form表單上傳

HTML代碼：

<!DOCTYPE html> <html> <head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><title>上傳文件</title> </head> <body><form id="my_form" name="form" action="/index" method="POST" enctype="multipart/form-data" ><input name="fff" id="my_file" type="file" /><input type="submit" value="提交" /></form> </body> </html>

Python代碼：

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.webclass MainHandler(tornado.web.RequestHandler):def get(self):self.render('index.html')def post(self, *args, **kwargs):file_metas = self.request.files["fff"]# print(file_metas)for meta in file_metas:file_name = meta['filename']with open(file_name,'wb') as up:up.write(meta['body'])settings = {'template_path': 'template', }application = tornado.web.Application([(r"/index", MainHandler), ], **settings)if __name__ == "__main__":application.listen(8000)tornado.ioloop.IOLoop.instance().start()

2、AJAX上傳

HTML - XMLHttpRequest：

<!DOCTYPE html> <html> <head lang="en"><meta charset="UTF-8"><title></title> </head> <body><input type="file" id="img" /><input type="button" onclick="UploadFile();" /><script>function UploadFile(){var fileObj = document.getElementById("img").files[0];var form = new FormData();form.append("k1", "v1");form.append("fff", fileObj);var xhr = new XMLHttpRequest();xhr.open("post", '/index', true);xhr.send(form);}</script> </body> </html>

HTML - jQuery：

<!DOCTYPE html> <html> <head lang="en"><meta charset="UTF-8"><title></title> </head> <body><input type="file" id="img" /><input type="button" onclick="UploadFile();" /><script>function UploadFile(){var fileObj = $("#img")[0].files[0];var form = new FormData();form.append("k1", "v1");form.append("fff", fileObj);$.ajax({type:'POST',url: '/index',data: form,processData: false, // tell jQuery not to process the datacontentType: false, // tell jQuery not to set contentTypesuccess: function(arg){console.log(arg);}})}</script> </body> </html>

HTML - iframe：

<!DOCTYPE html> <html> <head lang="en"><meta charset="UTF-8"><title></title> </head> <body><form id="my_form" name="form" action="/index" method="POST" enctype="multipart/form-data" ><div id="main"><input name="fff" id="my_file" type="file" /><input type="button" name="action" value="Upload" onclick="redirect()"/><iframe id='my_iframe' name='my_iframe' src="" class="hide"></iframe></div></form><script>function redirect(){document.getElementById('my_iframe').onload = Testt;document.getElementById('my_form').target = 'my_iframe';document.getElementById('my_form').submit();}function Testt(ths){var t = $("#my_iframe").contents().find("body").text();console.log(t);}</script> </body> </html>

Python代碼：

擴(kuò)展：基于iframe實(shí)現(xiàn)Ajax上傳示例：

py代碼：

$('#upload_iframe').load(function(){var iframeContents = this.contentWindow.document.body.innerText;iframeContents = JSON.parse(iframeContents);})

其他：

八、驗(yàn)證碼

驗(yàn)證碼原理在于后臺(tái)自動(dòng)創(chuàng)建一張帶有隨機(jī)內(nèi)容的圖片，然后將內(nèi)容通過(guò)img標(biāo)簽輸出到頁(yè)面。

安裝圖像處理模塊：

pip3 install pillow

示例截圖：

驗(yàn)證碼Demo源碼下載：這里

九、異步非阻塞

1、基本使用

裝飾器 + Future 從而實(shí)現(xiàn)Tornado的異步非阻塞

class AsyncHandler(tornado.web.RequestHandler):@gen.coroutinedef get(self):future = Future()future.add_done_callback(self.doing)yield future# 或# tornado.ioloop.IOLoop.current().add_future(future,self.doing)# yield futuredef doing(self,*args, **kwargs):self.write('async')self.finish()

當(dāng)發(fā)送GET請(qǐng)求時(shí)，由于方法被@gen.coroutine裝飾且yield 一個(gè) Future對(duì)象，那么Tornado會(huì)等待，等待用戶(hù)向future對(duì)象中放置數(shù)據(jù)或者發(fā)送信號(hào)，如果獲取到數(shù)據(jù)或信號(hào)之后，就開(kāi)始執(zhí)行doing方法。

異步非阻塞體現(xiàn)在當(dāng)在Tornaod等待用戶(hù)向future對(duì)象中放置數(shù)據(jù)時(shí)，還可以處理其他請(qǐng)求。

注意：在等待用戶(hù)向future對(duì)象中放置數(shù)據(jù)或信號(hào)時(shí)，此連接是不斷開(kāi)的。

2、同步阻塞和異步非阻塞對(duì)比

同步阻塞：

class SyncHandler(tornado.web.RequestHandler):def get(self):self.doing()self.write('sync')def doing(self):time.sleep(10)

異步非阻塞：

class AsyncHandler(tornado.web.RequestHandler):@gen.coroutinedef get(self):future = Future()tornado.ioloop.IOLoop.current().add_timeout(time.time() + 5, self.doing)yield futuredef doing(self, *args, **kwargs):self.write('async')self.finish()

3、httpclient類(lèi)庫(kù)

Tornado提供了httpclient類(lèi)庫(kù)用于發(fā)送Http請(qǐng)求，其配合Tornado的異步非阻塞使用。

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.web from tornado import gen from tornado import httpclient# 方式一： class AsyncHandler(tornado.web.RequestHandler):@gen.coroutinedef get(self, *args, **kwargs):print('進(jìn)入')http = httpclient.AsyncHTTPClient()data = yield http.fetch("http://www.google.com")print('完事',data)self.finish('6666')# 方式二： # class AsyncHandler(tornado.web.RequestHandler): # @gen.coroutine # def get(self): # print('進(jìn)入') # http = httpclient.AsyncHTTPClient() # yield http.fetch("http://www.google.com", self.done) # # def done(self, response): # print('完事') # self.finish('666')application = tornado.web.Application([(r"/async", AsyncHandler), ])if __name__ == "__main__":application.listen(8888)tornado.ioloop.IOLoop.instance().start()

基于異步非阻塞和Tornado-MySQL實(shí)現(xiàn)用戶(hù)登錄示例：

#!/usr/bin/env python # -*- coding:utf-8 -*- """ 需要先安裝支持異步操作Mysql的類(lèi)庫(kù)： Tornado-MySQL： https://github.com/PyMySQL/Tornado-MySQL#installationpip3 install Tornado-MySQL"""import tornado.web from tornado import genimport tornado_mysql from tornado_mysql import poolsPOOL = pools.Pool(dict(host='127.0.0.1', port=3306, user='root', passwd='123', db='cmdb'),max_idle_connections=1,max_recycle_sec=3)@gen.coroutine def get_user_by_conn_pool(user):cur = yield POOL.execute("SELECT SLEEP(%s)", (user,))row = cur.fetchone()raise gen.Return(row)@gen.coroutine def get_user(user):conn = yield tornado_mysql.connect(host='127.0.0.1', port=3306, user='root', passwd='123', db='cmdb',charset='utf8')cur = conn.cursor()# yield cur.execute("SELECT name,email FROM web_models_userprofile where name=%s", (user,))yield cur.execute("select sleep(10)")row = cur.fetchone()cur.close()conn.close()raise gen.Return(row)class LoginHandler(tornado.web.RequestHandler):def get(self, *args, **kwargs):self.render('login.html')@gen.coroutinedef post(self, *args, **kwargs):user = self.get_argument('user')data = yield gen.Task(get_user, user)if data:print(data)self.redirect('http://www.oldboyedu.com')else:self.render('login.html')application = tornado.web.Application([(r"/login", LoginHandler), ])if __name__ == "__main__":application.listen(8888)tornado.ioloop.IOLoop.instance().start()

自定義Web組件：

一、Session

1、面向?qū)ο蠡A(chǔ)

面向?qū)ο笾型ㄟ^(guò)索引的方式訪(fǎng)問(wèn)對(duì)象，需要內(nèi)部實(shí)現(xiàn) __getitem__ 、__delitem__、__setitem__方法

#!/usr/bin/env python # -*- coding:utf-8 -*-class Foo(object):def __getitem__(self, key):print '__getitem__',keydef __setitem__(self, key, value):print '__setitem__',key,valuedef __delitem__(self, key):print '__delitem__',keyobj = Foo() result = obj['k1'] #obj['k2'] = 'wupeiqi' #del obj['k1']

2、Tornado擴(kuò)展

Tornado框架中，默認(rèn)執(zhí)行Handler的get/post等方法之前默認(rèn)會(huì)執(zhí)行 initialize方法，所以可以通過(guò)自定義的方式使得所有請(qǐng)求在處理前執(zhí)行操作...

class BaseHandler(tornado.web.RequestHandler):def initialize(self):self.xxoo = "wupeiqi"class MainHandler(BaseHandler):def get(self):print(self.xxoo)self.write('index')class IndexHandler(BaseHandler):def get(self):print(self.xxoo)self.write('index')

3、session

session其實(shí)就是定義在服務(wù)器端用于保存用戶(hù)回話(huà)的容器，其必須依賴(lài)cookie才能實(shí)現(xiàn)。

自定義Session：

#!/usr/bin/env python # -*- coding:utf-8 -*- import config from hashlib import sha1 import os import timecreate_session_id = lambda: sha1(bytes('%s%s' % (os.urandom(16), time.time()), encoding='utf-8')).hexdigest()class SessionFactory:@staticmethoddef get_session_obj(handler):obj = Noneif config.SESSION_TYPE == "cache":obj = CacheSession(handler)elif config.SESSION_TYPE == "memcached":obj = MemcachedSession(handler)elif config.SESSION_TYPE == "redis":obj = RedisSession(handler)return objclass CacheSession:session_container = {}session_id = "__sessionId__"def __init__(self, handler):self.handler = handlerclient_random_str = handler.get_cookie(CacheSession.session_id, None)if client_random_str and client_random_str in CacheSession.session_container:self.random_str = client_random_strelse:self.random_str = create_session_id()CacheSession.session_container[self.random_str] = {}expires_time = time.time() + config.SESSION_EXPIREShandler.set_cookie(CacheSession.session_id, self.random_str, expires=expires_time)def __getitem__(self, key):ret = CacheSession.session_container[self.random_str].get(key, None)return retdef __setitem__(self, key, value):CacheSession.session_container[self.random_str][key] = valuedef __delitem__(self, key):if key in CacheSession.session_container[self.random_str]:del CacheSession.session_container[self.random_str][key]class RedisSession:def __init__(self, handler):passclass MemcachedSession:def __init__(self, handler):pass

4、分布式Session

一致性哈希：

#!/usr/bin/env python #coding:utf-8import sys import math from bisect import bisectif sys.version_info >= (2, 5):import hashlibmd5_constructor = hashlib.md5 else:import md5md5_constructor = md5.newclass HashRing(object):"""一致性哈希"""def __init__(self,nodes):'''初始化nodes : 初始化的節(jié)點(diǎn)，其中包含節(jié)點(diǎn)已經(jīng)節(jié)點(diǎn)對(duì)應(yīng)的權(quán)重默認(rèn)每一個(gè)節(jié)點(diǎn)有32個(gè)虛擬節(jié)點(diǎn)對(duì)于權(quán)重，通過(guò)多創(chuàng)建虛擬節(jié)點(diǎn)來(lái)實(shí)現(xiàn)如：nodes = [{'host':'127.0.0.1:8000','weight':1},{'host':'127.0.0.1:8001','weight':2},{'host':'127.0.0.1:8002','weight':1},]'''self.ring = dict()self._sorted_keys = []self.total_weight = 0self.__generate_circle(nodes)def __generate_circle(self,nodes):for node_info in nodes:self.total_weight += node_info.get('weight',1)for node_info in nodes:weight = node_info.get('weight',1)node = node_info.get('host',None)virtual_node_count = math.floor((32*len(nodes)*weight) / self.total_weight)for i in xrange(0,int(virtual_node_count)):key = self.gen_key_thirty_two( '%s-%s' % (node, i) )if self._sorted_keys.__contains__(key):raise Exception('該節(jié)點(diǎn)已經(jīng)存在.')self.ring[key] = nodeself._sorted_keys.append(key)def add_node(self,node):''' 新建節(jié)點(diǎn)node : 要添加的節(jié)點(diǎn)，格式為：{'host':'127.0.0.1:8002','weight':1}，其中第一個(gè)元素表示節(jié)點(diǎn)，第二個(gè)元素表示該節(jié)點(diǎn)的權(quán)重。'''node = node.get('host',None)if not node:raise Exception('節(jié)點(diǎn)的地址不能為空.')weight = node.get('weight',1)self.total_weight += weightnodes_count = len(self._sorted_keys) + 1virtual_node_count = math.floor((32 * nodes_count * weight) / self.total_weight)for i in xrange(0,int(virtual_node_count)):key = self.gen_key_thirty_two( '%s-%s' % (node, i) )if self._sorted_keys.__contains__(key):raise Exception('該節(jié)點(diǎn)已經(jīng)存在.')self.ring[key] = nodeself._sorted_keys.append(key)def remove_node(self,node):''' 移除節(jié)點(diǎn)node : 要移除的節(jié)點(diǎn) '127.0.0.1:8000''''for key,value in self.ring.items():if value == node:del self.ring[key]self._sorted_keys.remove(key)def get_node(self,string_key):'''獲取 string_key 所在的節(jié)點(diǎn)'''pos = self.get_node_pos(string_key)if pos is None:return Nonereturn self.ring[ self._sorted_keys[pos]].split(':')def get_node_pos(self,string_key):'''獲取 string_key 所在的節(jié)點(diǎn)的索引'''if not self.ring:return Nonekey = self.gen_key_thirty_two(string_key)nodes = self._sorted_keyspos = bisect(nodes, key)return posdef gen_key_thirty_two(self, key):m = md5_constructor()m.update(key)return long(m.hexdigest(), 16)def gen_key_sixteen(self,key):b_key = self.__hash_digest(key)return self.__hash_val(b_key, lambda x: x)def __hash_val(self, b_key, entry_fn):return (( b_key[entry_fn(3)] << 24)|(b_key[entry_fn(2)] << 16)|(b_key[entry_fn(1)] << 8)| b_key[entry_fn(0)] )def __hash_digest(self, key):m = md5_constructor()m.update(key)return map(ord, m.digest())""" nodes = [{'host':'127.0.0.1:8000','weight':1},{'host':'127.0.0.1:8001','weight':2},{'host':'127.0.0.1:8002','weight':1}, ]ring = HashRing(nodes) result = ring.get_node('98708798709870987098709879087') print result"""

session：

from hashlib import sha1 import os, timecreate_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_valuerequest.set_cookie(Session.session_id, self._id)def __getitem__(self, key):# 根據(jù) self._id ，在一致性哈西中找到其對(duì)應(yīng)的服務(wù)器IP# 找到相對(duì)應(yīng)的redis服務(wù)器，如： r = redis.StrictRedis(host='localhost', port=6379, db=0)# 使用python redis api 鏈接# 獲取數(shù)據(jù)，即：# return self._redis.hget(self._id, name)def __setitem__(self, key, value):# 根據(jù) self._id ，在一致性哈西中找到其對(duì)應(yīng)的服務(wù)器IP# 使用python redis api 鏈接# 設(shè)置session# self._redis.hset(self._id, name, value)def __delitem__(self, key):# 根據(jù) self._id 找到相對(duì)應(yīng)的redis服務(wù)器# 使用python redis api 鏈接# 刪除，即：return self._redis.hdel(self._id, name)

二、表單驗(yàn)證

在Web程序中往往包含大量的表單驗(yàn)證的工作，如：判斷輸入是否為空，是否符合規(guī)則。

HTML：

<!DOCTYPE html> <html> <head lang="en"><meta charset="UTF-8"><title></title><link href="{{static_url("commons.css")}}" rel="stylesheet" /> </head> <body><h1>hello</h1><form action="/index" method="post"><p>hostname: <input type="text" name="host" /> </p><p>ip: <input type="text" name="ip" /> </p><p>port: <input type="text" name="port" /> </p><p>phone: <input type="text" name="phone" /> </p><input type="submit" /></form> </body> </html>

Python：

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.web from hashlib import sha1 import os, time import reclass 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)# 讓提交的數(shù)據(jù) 和定義的正則表達(dá)式進(jìn)行匹配ret = re.match(regular, post_value)print key,ret,post_valueclass 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()

由于驗(yàn)證規(guī)則可以代碼重用，所以可以如此定義：

#!/usr/bin/env python # -*- coding:utf-8 -*-import tornado.ioloop import tornado.web import reclass Field(object):def __init__(self, error_msg_dict, required):self.id_valid = Falseself.value = Noneself.error = Noneself.name = Noneself.error_msg = error_msg_dictself.required = requireddef match(self, name, value):self.name = nameif not self.required:self.id_valid = Trueself.value = valueelse:if not value:if self.error_msg.get('required', None):self.error = self.error_msg['required']else:self.error = "%s is required" % nameelse:ret = re.match(self.REGULAR, value)if ret:self.id_valid = Trueself.value = ret.group()else:if self.error_msg.get('valid', None):self.error = self.error_msg['valid']else:self.error = "%s is invalid" % nameclass IPField(Field):REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"def __init__(self, error_msg_dict=None, required=True):error_msg = {} # {'required': 'IP不能為空', 'valid': 'IP格式錯(cuò)誤'}if error_msg_dict:error_msg.update(error_msg_dict)super(IPField, self).__init__(error_msg_dict=error_msg, required=required)class IntegerField(Field):REGULAR = "^\d+$"def __init__(self, error_msg_dict=None, required=True):error_msg = {'required': '數(shù)字不能為空', 'valid': '數(shù)字格式錯(cuò)誤'}if error_msg_dict:error_msg.update(error_msg_dict)super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required)class CheckBoxField(Field):def __init__(self, error_msg_dict=None, required=True):error_msg = {} # {'required': 'IP不能為空', 'valid': 'IP格式錯(cuò)誤'}if error_msg_dict:error_msg.update(error_msg_dict)super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required)def match(self, name, value):self.name = nameif not self.required:self.id_valid = Trueself.value = valueelse:if not value:if self.error_msg.get('required', None):self.error = self.error_msg['required']else:self.error = "%s is required" % nameelse:if isinstance(name, list):self.id_valid = Trueself.value = valueelse:if self.error_msg.get('valid', None):self.error = self.error_msg['valid']else:self.error = "%s is invalid" % nameclass FileField(Field):REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$"def __init__(self, error_msg_dict=None, required=True):error_msg = {} # {'required': '數(shù)字不能為空', 'valid': '數(shù)字格式錯(cuò)誤'}if error_msg_dict:error_msg.update(error_msg_dict)super(FileField, self).__init__(error_msg_dict=error_msg, required=required)def match(self, name, value):self.name = nameself.value = []if not self.required:self.id_valid = Trueself.value = valueelse:if not value:if self.error_msg.get('required', None):self.error = self.error_msg['required']else:self.error = "%s is required" % nameelse:m = re.compile(self.REGULAR)if isinstance(value, list):for file_name in value:r = m.match(file_name)if r:self.value.append(r.group())self.id_valid = Trueelse:self.id_valid = Falseif self.error_msg.get('valid', None):self.error = self.error_msg['valid']else:self.error = "%s is invalid" % namebreakelse:if self.error_msg.get('valid', None):self.error = self.error_msg['valid']else:self.error = "%s is invalid" % namedef save(self, request, upload_path=""):file_metas = request.files[self.name]for meta in file_metas:file_name = meta['filename']with open(file_name,'wb') as up:up.write(meta['body'])class Form(object):def __init__(self):self.value_dict = {}self.error_dict = {}self.valid_status = Truedef validate(self, request, depth=10, pre_key=""):self.initialize()self.__valid(self, request, depth, pre_key)def initialize(self):passdef __valid(self, form_obj, request, depth, pre_key):"""驗(yàn)證用戶(hù)表單請(qǐng)求的數(shù)據(jù):param form_obj: Form對(duì)象（Form派生類(lèi)的對(duì)象）:param request: Http請(qǐng)求上下文（用于從請(qǐng)求中獲取用戶(hù)提交的值）:param depth: 對(duì)Form內(nèi)容的深度的支持:param pre_key: Html中name屬性值的前綴（多層Form時(shí)，內(nèi)部遞歸時(shí)設(shè)置，無(wú)需理會(huì)）:return: 是否驗(yàn)證通過(guò)，True：驗(yàn)證成功；False：驗(yàn)證失敗"""depth -= 1if depth < 0:return Noneform_field_dict = form_obj.__dict__for key, field_obj in form_field_dict.items():print key,field_objif isinstance(field_obj, Form) or isinstance(field_obj, Field):if isinstance(field_obj, Form):# 獲取以key開(kāi)頭的所有的值，以參數(shù)的形式傳至self.__valid(field_obj, request, depth, key)continueif pre_key:key = "%s.%s" % (pre_key, key)if isinstance(field_obj, CheckBoxField):post_value = request.get_arguments(key, None)elif isinstance(field_obj, FileField):post_value = []file_list = request.request.files.get(key, None)for file_item in file_list:post_value.append(file_item['filename'])else:post_value = request.get_argument(key, None)print post_value# 讓提交的數(shù)據(jù) 和定義的正則表達(dá)式進(jìn)行匹配field_obj.match(key, post_value)if field_obj.id_valid:self.value_dict[key] = field_obj.valueelse:self.error_dict[key] = field_obj.errorself.valid_status = Falseclass ListForm(object):def __init__(self, form_type):self.form_type = form_typeself.valid_status = Trueself.value_dict = {}self.error_dict = {}def validate(self, request):name_list = request.request.arguments.keys() + request.request.files.keys()index = 0flag = Falsewhile True:pre_key = "[%d]" % indexfor name in name_list:if name.startswith(pre_key):flag = Truebreakif flag:form_obj = self.form_type()form_obj.validate(request, depth=10, pre_key="[%d]" % index)if form_obj.valid_status:self.value_dict[index] = form_obj.value_dictelse:self.error_dict[index] = form_obj.error_dictself.valid_status = Falseelse:breakindex += 1flag = Falseclass MainForm(Form):def __init__(self):# self.ip = IPField(required=True)# self.port = IntegerField(required=True)# self.new_ip = IPField(required=True)# self.second = SecondForm()self.fff = FileField(required=True)super(MainForm, self).__init__()# # class SecondForm(Form): # # def __init__(self): # self.ip = IPField(required=True) # self.new_ip = IPField(required=True) # # super(SecondForm, self).__init__()class MainHandler(tornado.web.RequestHandler):def get(self):self.render('index.html')def post(self, *args, **kwargs):# for i in dir(self.request):# print i# print self.request.arguments# print self.request.files# print self.request.query# name_list = self.request.arguments.keys() + self.request.files.keys()# print name_list# list_form = ListForm(MainForm)# list_form.validate(self)## print list_form.valid_status# print list_form.value_dict# print list_form.error_dict# obj = MainForm()# obj.validate(self)## print "驗(yàn)證結(jié)果：", obj.valid_status# print "符合驗(yàn)證結(jié)果：", obj.value_dict# print "錯(cuò)誤信息:"# for key, item in obj.error_dict.items():# print key,item# print self.get_arguments('favor'),type(self.get_arguments('favor'))# print self.get_argument('favor'),type(self.get_argument('favor'))# print type(self.get_argument('fff')),self.get_argument('fff')# print self.request.files# obj = MainForm()# obj.validate(self)# print obj.valid_status# print obj.value_dict# print obj.error_dict# print self.request,type(self.request)# obj.fff.save(self.request)# from tornado.httputil import HTTPServerRequest# name_list = self.request.arguments.keys() + self.request.files.keys()# print name_list# print self.request.files,type(self.request.files)# print len(self.request.files.get('fff'))# obj = MainForm()# obj.validate(self)# print obj.valid_status# print obj.value_dict# print obj.error_dict# obj.fff.save(self.request)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()

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