Python開發【第十五篇】：Web框架之Tornado
概述
Tornado 是 FriendFeed 使用的可擴展的非阻塞式 web 服務器及其相關工具的開源版本。這個 Web 框架看起來有些像web.py 或者 Google 的 webapp，不過爲了能有效利用非阻塞式服務器環境，這個 Web 框架還包含了一些相關的有用工具 和優化。javascript
Tornado 和如今的主流 Web 服務器框架（包括大多數 Python 的框架）有着明顯的區別：它是非阻塞式服務器，並且速度至關快。得利於其 非阻塞的方式和對 epoll 的運用，Tornado 每秒能夠處理數以千計的鏈接，這意味着對於實時 Web 服務來講，Tornado 是一個理想的 Web 框架。咱們開發這個 Web 服務器的主要目的就是爲了處理 FriendFeed 的實時功能 ——在 FriendFeed 的應用裏每個活動用戶都會保持着一個服務器鏈接。（關於如何擴容 服務器，以處理數以千計的客戶端的鏈接的問題，請參閱 C10K problem。）css
下載安裝：html
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pip3 install tornado
源碼安裝
https:
/
/
pypi.python.org
/
packages
/
source
/
t
/
tornado
/
tornado
-
4.3
.tar.gz
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框架使用
1、快速上手java
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#!/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()
|
執行過程：node
- 第一步：執行腳本，監聽 8888 端口
- 第二步：瀏覽器客戶端訪問 /index --> http://127.0.0.1:8888/index
- 第三步：服務器接受請求，並交由對應的類處理該請求
- 第四步：類接受到請求以後，根據請求方式（post / get / delete ...）的不一樣調用並執行相應的方法
- 第五步：方法返回值的字符串內容發送瀏覽器
#!/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 gen import uimodules as md import uimethods as mt class MainHandler(tornado.web.RequestHandler): @asynchronous @gen.coroutine def 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.body 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()
2、路由系統python
路由系統其實就是 url 和 類 的對應關係，這裏不一樣於其餘框架，其餘不少框架均是 url 對應 函數，Tornado中每一個url對應的是一個類。jquery
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#!/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()
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Tornado中原生支持二級域名的路由，如：git
3、模板引擎github
Tornao中的模板語言和django中相似，模板引擎將模板文件載入內存，而後將數據嵌入其中，最終獲取到一個完整的字符串，再將字符串返回給請求者。web
Tornado 的模板支持「控制語句」和「表達語句」，控制語句是使用 {% 和 %} 包起來的 例如 {% if len(items) > 2 %}。表達語句是使用 {{ 和 }} 包起來的，例如 {{ items[0] }}。
控制語句和對應的 Python 語句的格式基本徹底相同。咱們支持 if、for、while 和 try，這些語句邏輯結束的位置須要用 {% end %} 作標記。還經過 extends 和 block 語句實現了模板繼承。這些在 template 模塊 的代碼文檔中有着詳細的描述。
注：在使用模板前須要在setting中設置模板路徑："template_path" : "tpl"
一、基本使用
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class 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()
<!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>
在模板中默認提供了一些函數、字段、類以供模板使用：
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: 當前的 RequestHandler 對象
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
二、母版
<!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>
{% 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 %}
三、導入
<div> <ul> <li>1024</li> <li>42區</li> </ul> </div>
<!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>
四、自定義UIMethod以UIModule
a. 定義
# uimethods.py def tab(self): return 'UIMethod'
#!/usr/bin/env python # -*- coding:utf-8 -*- from tornado.web import UIModule from tornado import escape class custom(UIModule): def render(self, *args, **kwargs): return escape.xhtml_escape('<h1>wupeiqi</h1>') #return escape.xhtml_escape('<h1>wupeiqi</h1>')
b. 註冊
#!/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 mt class 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()
c. 使用
<!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> {% module custom(123) %} {{ tab() }} </body>
4、靜態文件
對於靜態文件，能夠配置靜態文件的目錄和前段使用時的前綴，而且Tornaodo還支持靜態文件緩存。
#!/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', '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()
<!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>
注：靜態文件緩存的實現
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. The default 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()
5、cookie
Tornado中能夠對cookie進行操做，而且還能夠對cookie進行簽名以放置僞造。
一、基本操做
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!")
二、加密cookie（簽名）
Cookie 很容易被惡意的客戶端僞造。加入你想在 cookie 中保存當前登錄用戶的 id 之類的信息，你須要對 cookie 做簽名以防止僞造。Tornado 經過 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，你須要在建立應用時提供一個密鑰，名字爲 cookie_secret。 你能夠把它做爲一個關鍵詞參數傳入應用的設置中：
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=")
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_VERSION if clock is None: clock = time.time timestamp = 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 value elif 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 + signature else: 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 None signature = _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 None timestamp = int(parts[1]) if timestamp < clock() - max_age_days * 86400: gen_log.warning("Expired cookie %r", value) return None if 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 None if parts[1].startswith(b"0"): gen_log.warning("Tampered cookie %r", value) return None try: return base64.b64decode(parts[0]) except Exception: return None def _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, rest rest = value[2:] # remove version number key_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_sig def _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 None signed_string = value[:-len(passed_sig)] if isinstance(secret, dict): try: secret = secret[key_version] except KeyError: return None expected_sig = _create_signature_v2(secret, signed_string) if not _time_independent_equals(passed_sig, expected_sig): return None if name_field != utf8(name): return None timestamp = int(timestamp) if timestamp < clock() - max_age_days * 86400: # The signature has expired. return None try: return base64.b64decode(value_field) except Exception: return None def get_signature_key_version(value): value = utf8(value) version = _get_version(value) if version < 2: return None try: key_version, _, _, _, _ = _decode_fields_v2(value) except ValueError: return None return key_version
簽名Cookie的本質是：
寫cookie過程：
- 將值進行base64加密
- 對除值之外的內容進行簽名，哈希算法（沒法逆向解析）
- 拼接 簽名 + 加密值
讀cookie過程：
- 讀取 簽名 + 加密值
- 對簽名進行驗證
- base64解密，獲取值內容
注：許多API驗證機制和安全cookie的實現機制相同。
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class 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': '用戶名或密碼錯誤'}) 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()
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class BaseHandler(tornado.web.RequestHandler): def get_current_user(self): return self.get_secure_cookie("login_user") class MainHandler(BaseHandler): @tornado.web.authenticated def get(self): login_user = self.current_user self.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': '用戶名或密碼錯誤'}) 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()
三、JavaScript操做Cookie
因爲Cookie保存在瀏覽器端，因此在瀏覽器端也可使用JavaScript來操做Cookie。
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/*
設置cookie，指定秒數過時
*/
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();
}
|
對於參數：
- 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 專門用於操做cookie，猛擊這裏
6、CSRF
Tornado中的誇張請求僞造和Django中的類似，跨站僞造請求(Cross-site request forgery)
settings = {
"xsrf_cookies": True, } application = tornado.web.Application([ (r"/", MainHandler), (r"/login", LoginHandler), ], **settings)
<form action="/new_message" method="post"> {{ xsrf_form_html() }} <input type="text" name="message"/> <input type="submit" value="Post"/> </form>
function getCookie(name) {
var r = document.cookie.match("\\b" + name + "=([^;]*)\\b"); return r ? r[1] : undefined; } jQuery.postJSON = function(url, args, callback) { args._xsrf = getCookie("_xsrf"); $.ajax({url: url, data: $.param(args), dataType: "text", type: "POST", success: function(response) { callback(eval("(" + response + ")")); }}); };
注：Ajax使用時，本質上就是去獲取本地的cookie，攜帶cookie再來發送請求
7、上傳文件
一、Form表單上傳
<!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>
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class 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()
二、AJAX上傳
<!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>
<!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 data contentType: false, // tell jQuery not to set contentType success: function(arg){ console.log(arg); } }) } </script> </body> </html>
<!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>
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class 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()
<script type="text/javascript"> $(document).ready(function () { $("#formsubmit").click(function () { var iframe = $('<iframe name="postiframe" id="postiframe" style="display: none"></iframe>'); $("body").append(iframe); var form = $('#theuploadform'); form.attr("action", "/upload.aspx"); form.attr("method", "post"); form.attr("encoding", "multipart/form-data"); form.attr("enctype", "multipart/form-data"); form.attr("target", "postiframe"); form.attr("file", $('#userfile').val()); form.submit(); $("#postiframe").load(function () { iframeContents = this.contentWindow.document.body.innerHTML; $("#textarea").html(iframeContents); }); return false; }); }); </script> <form id="theuploadform"> <input id="userfile" name="userfile" size="50" type="file" /> <input id="formsubmit" type="submit" value="Send File" /> </form> <div id="textarea"> </div>
$('#upload_iframe').load(function(){ var iframeContents = this.contentWindow.document.body.innerText; iframeContents = JSON.parse(iframeContents); })
function bindChangeAvatar1() {
$('#avatarImg').change(function () { var file_obj = $(this)[0].files[0]; $('#prevViewImg')[0].src = window.URL.createObjectURL(file_obj) }) } function bindChangeAvatar2() { $('#avatarImg').change(function () { var file_obj = $(this)[0].files[0]; var reader = new FileReader(); reader.readAsDataURL(file_obj); reader.onload = function (e) { $('#previewImg')[0].src = this.result; }; }) } function bindChangeAvatar3() { $('#avatarImg').change(function () { var file_obj = $(this)[0].files[0]; var form = new FormData(); form.add('img_upload', file_obj); $.ajax({ url: '', data: form, processData: false, // tell jQuery not to process the data contentType: false, // tell jQuery not to set contentType success: function (arg) { } }) }) } function bindChangeAvatar4() { $('#avatarImg').change(function () { $(this).parent().submit(); $('#upload_iframe').load(function () { var iframeContents = this.contentWindow.document.body.innerText; iframeContents = JSON.parse(iframeContents); if (iframeContents.status) { $('#previewImg').attr('src', '/' + iframeContents.data); } }) }) }
8、驗證碼
驗證碼原理在於後臺自動建立一張帶有隨機內容的圖片，而後將內容經過img標籤輸出到頁面。
安裝圖像處理模塊：
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pip3 install pillow
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示例截圖：
驗證碼Demo源碼下載：猛擊這裏
9、異步非阻塞
一、基本使用
裝飾器 + Future 從而實現Tornado的異步非阻塞
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class
AsyncHandler(tornado.web.RequestHandler):
@gen
.coroutine
def
get(
self
):
future
=
Future()
future.add_done_callback(
self
.doing)
yield
future
# 或
# tornado.ioloop.IOLoop.current().add_future(future,self.doing)
# yield future
def
doing(
self
,
*
args,
*
*
kwargs):
self
.write(
'async'
)
self
.finish()
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當發送GET請求時，因爲方法被@gen.coroutine裝飾且yield 一個 Future對象，那麼Tornado會等待，等待用戶向future對象中放置數據或者發送信號，若是獲取到數據或信號以後，就開始執行doing方法。
異步非阻塞體如今當在Tornaod等待用戶向future對象中放置數據時，還能夠處理其餘請求。
注意：在等待用戶向future對象中放置數據或信號時，此鏈接是不斷開的。
二、同步阻塞和異步非阻塞對比
class SyncHandler(tornado.web.RequestHandler): def get(self): self.doing() self.write('sync') def doing(self): time.sleep(10)
class AsyncHandler(tornado.web.RequestHandler): @gen.coroutine def get(self): future = Future() tornado.ioloop.IOLoop.current().add_timeout(time.time() + 5, self.doing) yield future def doing(self, *args, **kwargs): self.write('async') self.finish()
三、httpclient類庫
Tornado提供了httpclient類庫用於發送Http請求，其配合Tornado的異步非阻塞使用。
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class
AsyncHandler(tornado.web.RequestHandler):
@gen
.coroutine
def
get(
self
):
from
tornado
import
httpclient
http
=
httpclient.AsyncHTTPClient()
yield
http.fetch(
"http://www.google.com"
,
self
.endding)
def
endding(
self
, response):
print
(
len
(response.body))
self
.write(
'ok'
)
self
.finish()
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自定義Web組件
1、Session
一、面向對象基礎
面向對象中經過索引的方式訪問對象，須要內部實現 __getitem__ 、__delitem__、__setitem__方法
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#!/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']
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二、Tornado擴展
Tornado框架中，默認執行Handler的get/post等方法以前默認會執行 initialize方法，因此能夠經過自定義的方式使得全部請求在處理前執行操做...
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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'
)
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三、session
session其實就是定義在服務器端用於保存用戶回話的容器，其必須依賴cookie才能實現。
#!/usr/bin/env python # -*- coding:utf-8 -*- import config from hashlib import sha1 import os import time create_session_id = lambda: sha1(bytes('%s%s' % (os.urandom(16), time.time()), encoding='utf-8')).hexdigest() class SessionFactory: @staticmethod def get_session_obj(handler): obj = None if config.SESSION_TYPE == "cache": obj = CacheSession(handler) elif config.SESSION_TYPE == "memcached": obj = MemcachedSession(handler) elif config.SESSION_TYPE == "redis": obj = RedisSession(handler) return obj class CacheSession: session_container = {} session_id = "__sessionId__" def __init__(self, handler): self.handler = handler client_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_str else: self.random_str = create_session_id() CacheSession.session_container[self.random_str] = {} expires_time = time.time() + config.SESSION_EXPIRES handler.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 ret def __setitem__(self, key, value): CacheSession.session_container[self.random_str][key] = value def __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): pass class MemcachedSession: def __init__(self, handler): pass
四、分佈式Session
#!/usr/bin/env python #coding:utf-8 import sys import math from bisect import bisect if sys.version_info >= (2, 5): import hashlib md5_constructor = hashlib.md5 else: import md5 md5_constructor = md5.new class HashRing(object): """一致性哈希""" def __init__(self,nodes): '''初始化 nodes : 初始化的節點，其中包含節點已經節點對應的權重 默認每個節點有32個虛擬節點 對於權重，經過多建立虛擬節點來實現 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 = 0 self.__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('該節點已經存在.') self.ring[key] = node self._sorted_keys.append(key) def add_node(self,node): ''' 新建節點 node : 要添加的節點，格式爲：{'host':'127.0.0.1:8002','weight':1}，其中第一個元素表示節點，第二個元素表示該節點的權重。 ''' node = node.get('host',None) if not node: raise Exception('節點的地址不能爲空.') weight = node.get('weight',1) self.total_weight += weight nodes_count = len(self._sorted_keys) + 1 virtual_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('該節點已經存在.') self.ring[key] = node self._sorted_keys.append(key) def remove_node(self,node): ''' 移除節點 node : 要移除的節點 '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 所在的節點''' pos = self.get_node_pos(string_key) if pos is None: return None return self.ring[ self._sorted_keys[pos]].split(':') def get_node_pos(self,string_key): '''獲取 string_key 所在的節點的索引''' if not self.ring: return None key = self.gen_key_thirty_two(string_key) nodes = self._sorted_keys pos = bisect(nodes, key) return pos def 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 """
from hashlib import sha1 import os, time 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): # 根據 self._id ，在一致性哈西中找到其對應的服務器IP # 找到相對應的redis服務器，如： r = redis.StrictRedis(host='localhost', port=6379, db=0) # 使用python redis api 連接 # 獲取數據，即： # return self._redis.hget(self._id, name) def __setitem__(self, key, value): # 根據 self._id ，在一致性哈西中找到其對應的服務器IP # 使用python redis api 連接 # 設置session # self._redis.hset(self._id, name, value) def __delitem__(self, key): # 根據 self._id 找到相對應的redis服務器 # 使用python redis api 連接 # 刪除，即： return self._redis.hdel(self._id, name)
2、表單驗證
在Web程序中每每包含大量的表單驗證的工做，如：判斷輸入是否爲空，是否符合規則。
<!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>
#!/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}$' def check_valid(self, request): form_dict = self.__dict__ for key, regular in form_dict.items(): post_value = request.get_argument(key) # 讓提交的數據 和 定義的正則表達式進行匹配 ret = re.match(regular, post_value) print key,ret,post_value class MainHandler(tornado.web.RequestHandler): def get(self): self.render('index.html') def post(self, *args, **kwargs): obj = MainForm() result = obj.check_valid(self) self.write('ok') settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', 'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh', 'login_url': '/login' } application = tornado.web.Application([ (r"/index", MainHandler), ], **settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
因爲驗證規則能夠代碼重用，因此能夠如此定義：
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web import re class Field(object): def __init__(self, error_msg_dict, required): self.id_valid = False self.value = None self.error = None self.name = None self.error_msg = error_msg_dict self.required = required def match(self, name, value): self.name = name if not self.required: self.id_valid = True self.value = value else: if not value: if self.error_msg.get('required', None): self.error = self.error_msg['required'] else: self.error = "%s is required" % name else: ret = re.match(self.REGULAR, value) if ret: self.id_valid = True self.value = ret.group() else: if self.error_msg.get('valid', None): self.error = self.error_msg['valid'] else: self.error = "%s is invalid" % name class IPField(Field): REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$" def __init__(self, error_msg_dict=None, required=True): error_msg = {} # {'required': 'IP不能爲空', 'valid': 'IP格式錯誤'} 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+$" def __init__(self, error_msg_dict=None, required=True): error_msg = {'required': '數字不能爲空', 'valid': '數字格式錯誤'} if error_msg_dict: error_msg.update(error_msg_dict) super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required) class CheckBoxField(Field): def __init__(self, error_msg_dict=None, required=True): error_msg = {} # {'required': 'IP不能爲空', 'valid': 'IP格式錯誤'} if error_msg_dict: error_msg.update(error_msg_dict) super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required) def match(self, name, value): self.name = name if not self.required: self.id_valid = True self.value = value else: if not value: if self.error_msg.get('required', None): self.error = self.error_msg['required'] else: self.error = "%s is required" % name else: if isinstance(name, list): self.id_valid = True self.value = value else: if self.error_msg.get('valid', None): self.error = self.error_msg['valid'] else: self.error = "%s is invalid" % name class FileField(Field): REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$" def __init__(self, error_msg_dict=None, required=True): error_msg = {} # {'required': '數字不能爲空', 'valid': '數字格式錯誤'} 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 = name self.value = [] if not self.required: self.id_valid = True self.value = value else: if not value: if self.error_msg.get('required', None): self.error = self.error_msg['required'] else: self.error = "%s is required" % name else: 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 = True else: self.id_valid = False if self.error_msg.get('valid', None): self.error = self.error_msg['valid'] else: self.error = "%s is invalid" % name break else: if self.error_msg.get('valid', None): self.error = self.error_msg['valid'] else: self.error = "%s is invalid" % name def 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 = True def validate(self, request, depth=10, pre_key=""): self.initialize() self.__valid(self, request, depth, pre_key) def initialize(self): pass def __valid(self, form_obj, request, depth, pre_key): """ 驗證用戶表單請求的數據 :param form_obj: Form對象（Form派生類的對象） :param request: Http請求上下文（用於從請求中獲取用戶提交的值） :param depth: 對Form內容的深度的支持 :param pre_key: Html中name屬性值的前綴（多層Form時，內部遞歸時設置，無需理會） :return: 是否驗證經過，True：驗證成功；False：驗證失敗 """ depth -= 1 if depth < 0: return None form_field_dict = form_obj.__dict__ for key, field_obj in form_field_dict.items(): print key,field_obj if isinstance(field_obj, Form) or isinstance(field_obj, Field): if isinstance(field_obj, Form): # 獲取以key開頭的全部的值，以參數的形式傳至 self.__valid(field_obj, request, depth, key) continue if 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 # 讓提交的數據 和 定義的正則表達式進行匹配 field_obj.match(key, post_value) if field_obj.id_valid: self.value_dict[key] = field_obj.value else: self.error_dict[key] = field_obj.error self.valid_status = False class ListForm(object): def __init__(self, form_type): self.form_type = form_type self.valid_status = True self.value_dict = {} self.error_dict = {} def validate(self, request): name_list = request.request.arguments.keys() + request.request.files.keys() index = 0 flag = False while True: pre_key = "[%d]" % index for name in name_list: if name.startswith(pre_key): flag = True break if 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_dict else: self.error_dict[index] = form_obj.error_dict self.valid_status = False else: break index += 1 flag = False class 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 "驗證結果：", obj.valid_status # print "符合驗證結果：", obj.value_dict # print "錯誤信息:" # 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()