第13章 Python的HTML應用
本章的知識點：
一、HTML的標籤；
二、URL的處理，包含解析、拼合和分解等；
三、URL的編解嗎；
四、urllib模塊的使用；
內容：
13.1 HTML介紹
13.1.1 HTML的歷史
13.1.2 SGML、HTML、XHTML、HTML5的關係
13.1.3 HTML的標籤
13.1.4 HTML的框架組件
13.2 URL的處理
13.2.1 統一資源定位符UR
| 協議名稱 | 協議含義 | 協議名稱 | 協議含義 |
| http | 超文本傳送協議 | mailto | 電子郵件 |
| https | 使用安全套接層的超文本傳送協議 | file | 本地計算機上的文件 |
| ftp | 文件傳輸協議 | telnet | Telnt協議 |
13.2.2 URL的解析
| 屬 性 | 索引值 | 值 | 若是不包含的值 | 屬 性 | 索引值 | 值 | 若是不包含的值 |
| scheme | 0 | 協議 | 空字符串 | fragment | 5 | 分片部分 | 空字符串 |
| netloc | 1 | 服務器地址 | 空字符串 | username | 用戶名 | None | |
| path | 2 | 路徑 | 空字符串 | password | 密碼 | None | |
| params | 3 | 參數 | 空字符串 | hostname | 主機名 | None | |
| query | 4 | 查詢部分 | 空字符串 | port | 端口 | None |
1 from urllib.parse import urlparse 2 r = urlparse('http://alice:secret@www.hostname.com:80/%7Ealice/python.cgi?query=text#sample') 3 print (r) 4 # 輸出：ParseResult(scheme='http', netloc='alice:secret@www.hostname.com:80', path='/%7Ealice/python.cgi', params='', query='query=text', fragment='sample')
1 from urllib.parse import urlparse 2 r = urlparse('http://alice:secret@www.hostname.com:80/%7Ealice/python.cgi?query=text#sample') 3 print (r) 4 print (r.scheme) 5 print (r.netloc) 6 print (r.path) 7 print (r.params) 8 print (r.query) 9 print (r.fragment) 10 print (r.username) 11 print (r.password) 12 print (r.hostname) 13 print (r.port) 14 print (r.geturl()) 15 r2 = urlparse("www.python.org/about","http") 16 print (r2) 17 # 輸出：ParseResult(scheme='http', netloc='alice:secret@www.hostname.com:80', path='/%7Ealice/python.cgi', params='', query='query=text', fragment='sample') 18 # http 19 # alice:secret@www.hostname.com:80 20 # /%7Ealice/python.cgi 21 # 22 # query=text 23 # sample 24 # alice 25 # secret 26 # www.hostname.com 27 # 80 28 # http://alice:secret@www.hostname.com:80/%7Ealice/python.cgi?query=text#sample 29 # ParseResult(scheme='http', netloc='', path='www.python.org/about', params='', query='', fragment='')
13.2.3 URL的拼合
1 from urllib.parse import urljoin,urlsplit,urlunsplit 2 r = urljoin("http://www.zeroc.com", "ice.html") 3 print (r) 4 r2 = urljoin("","") 5 print (r2) 6 # 輸出：http://www.zeroc.com/ice.html
1 from urllib.parse import urljoin,urlsplit,urlunsplit 2 r = urljoin("http://www.zeroc.com", "ftp://www.zeroc.com/ftp") 3 print (r) 4 r2 = urljoin("http://www.zeroc.com", "www.zeroc.com/ftp") 5 print (r2) 6 r3 = urljoin("http://www.zeroc.com", "http://www.zeroc.com/ftp") 7 print (r3) 8 # 輸出：ftp://www.zeroc.com/ftp 9 # http://www.zeroc.com/www.zeroc.com/ftp 10 # http://www.zeroc.com/ftp
13.2.4 URL的分析
1 r = urlsplit("http://www.python.org:80/faq.cgi?src=fie") 2 print (r)
1 r = urlsplit("http://www.python.org:80/faq.cgi?src=fie") 2 print (r) 3 4 r = urlunsplit("http", "www.python.org", "faq", "", "") 5 print (r) 6 7 r = urlunsplit(urlsplit("http://www.python.org/faq")) 8 print (r)
1 from urllib.parse import urlparse,urljoin,urlunsplit 2 abs_urls = ["http://www.python.org", "ftp://www.linux.org", "http://www.gtk.org", "file://"] 3 rel_url = "faq.html" 4 for abs_url in abs_urls: 5 url = urljoin(abs_url, rel_url) 6 expected_url = url 7 scheme, netloc, path, query, fragment = urlsplit(url) 8 if scheme or scheme == "file": 9 print (url, "====> None") 10 continue 11 if scheme is not "ftp": 12 expected_url = urlunsplit(('http', netloc, path, query, fragment)) 13 print (url, "====>", expected_url)
13.2.5 URL的編解碼
| 保留字符 | URL 編碼 | 保留字符 | URL 編碼 | 保留字符 | URL 編碼 |
| ； | %3B | : | %3A | = | %3D |
| / | %2F | @ | %40 | & | %26 |
| ？ | %3F |
| 保留字符 | URL 編碼 | 保留字符 | URL 編碼 | 保留字符 | URL 編碼 |
| < | %3C | { | %7B | %7E | |
| > | %3E | } | %7D | [ | %5B |
| " | %22 | | | %7C | ] | %5D |
| # | %23 | \ | %5C | ' | %60 |
| % | %25 | ^ | %5E |
| 方法 | 功能 | 方法 | 功能 |
| quote | 對URL進行編碼 | unquote | 對URL進行解碼 |
| quote_plus | 同quote方法，進一步將空格表示成+符合 | unquote_plus | 同unquote方法，進一步將+符合變成空格 |
13.2.5 URL的編解碼
1 from urllib.parse import quote,quote_plus, unquote, unquote_plus 2 r1 = quote("/-test") 3 print (r1) 4 r2 = quote("/-test/public html") 5 print (r2) 6 r3 = quote_plus("/-test/public html") 7 print (r3) 8 unquote_plus(r3) 9 unquote_plus(r2) 10 r = quote("/-test", "-/") 11 # 輸出：/-test 12 # /-test/public%20html 13 # %2F-test%2Fpublic+html
13.2.6 中文的編解碼
1 quote("URL編碼") 2 r = quote("URL編碼") 3 unquote(r) 4 print (unquote(r))
13.2.7 查詢參數的編碼
1 from urllib.parse import * 2 urlencode([('keyword1', 'value1'), ('keyword2', 'value2')]) 3 urlencode() 4 urlencode({'keyword1':'value1', 'keyword2':'value2'}) 5 a = {'keyword1':'value1', 'keyword2':'value2'} 6 b = {'keyword2':'value2', 'keyword1':'value1'} 7 a is b 8 a == b 9 urlencode([('keyword1',('value1', 'value2','value12') )]) 10 urllib.urlencode([('keyword1',('value1', 'value2','value12') )], True) 11 r = urlencode([('keyword1',('value1', 'value2','value12') )]) 12 unquote_plus(r)
13.3 CGL的使用
13.3.1 CGL介紹
| 類型 | 子類型 | 說明 | 類型 | 子類型 | 說明 |
| Application | Octet-stream | MIME編碼的二進制數據 | Multipart | Mixed digest | 混合類型，能夠支持等操做文件上傳 |
| Audio | Basic | 音頻文件 | Text | Html、Plain | HTML文檔，純文本文檔 |
| Image | Gif、Jpeg | 圖文文件 | Video | mpeg | 視頻文件 |
| Message | External-body | 對信息的封裝 | |||
1 print ("Content-Type:text/html") 2 print () 3 print ("Content-Type:text/html\n\n") 4 print ('<!DOCTYPE html">') 5 print ('<html>') 6 print ('<head>') 7 print ('<br>©2009') 8 print ('</body>') 9 print ('<html>') 10 # 輸出：Content-Type:text/html 11 # 12 # Content-Type:text/html 13 # 14 # 15 # <!DOCTYPE html"> 16 # <html> 17 # <head> 18 # <br>©2009 19 # </body> 20 # <html>
13.3.2 獲取CGL環境信息
1 #！E：/Python3/python.exe 2 print ("Content-Type:text/html\n\n") 3 import datetime 4 print (datetime.datetime.now()) 5 #輸出：Content-Type:text/html 6 # 7 # 8 # 2019-01-06 18:00:37.908176
1 #！E：/Python3/python.exe 2 import os 3 print ("Content-Type:text/html\n\n") 4 remote_addr = os.environ['REMOTE_ADDR'] 5 if remote_addr == '127.0.0.1': 6 print ("來自本地的訪問") 7 else: 8 print ("來自外部的訪問")
1 #！E：/Python3/python.exe 2 print ("Content-Type:text/html\n\n") 3 import cgi 4 cgi.print_environ() 5 # 輸出：Content-Type:text/html 6 # 7 # 8 # 9 # <H3>Shell Environment:</H3> 10 # <DL> 11 # <DT> ALLUSERSPROFILE <DD> C:\ProgramData 12 # <DT> APPDATA <DD> C:\Users\劉永峯\AppData\Roaming 13 # <DT> COMMONPROGRAMFILES <DD> C:\Program Files\Common Files 14 # <DT> COMMONPROGRAMFILES(X86) <DD> C:\Program Files (x86)\Common Files 15 # <DT> COMMONPROGRAMW6432 <DD> C:\Program Files\Common Files 16 # <DT> COMPUTERNAME <DD> LAPTOP-PJ9B1NQR 17 # <DT> COMSPEC <DD> C:\windows\system32\cmd.exe 18 # <DT> CONFIGSETROOT <DD> C:\windows\ConfigSetRoot 19 # <DT> DRIVERDATA <DD> C:\Windows\System32\Drivers\DriverData 20 # <DT> FPS_BROWSER_APP_PROFILE_STRING <DD> Internet Explorer 21 # <DT> FPS_BROWSER_USER_PROFILE_STRING <DD> Default 22 # <DT> HOMEDRIVE <DD> C: 23 # <DT> HOMEPATH <DD> \Users\劉永峯 24 # <DT> LOCALAPPDATA <DD> C:\Users\劉永峯\AppData\Local 25 # <DT> LOGONSERVER <DD> \\LAPTOP-PJ9B1NQR 26 # <DT> NUMBER_OF_PROCESSORS <DD> 4 27 # <DT> ONEDRIVE <DD> C:\Users\劉永峯\OneDrive 28 # <DT> ONEDRIVECONSUMER <DD> C:\Users\劉永峯\OneDrive 29 # <DT> OS <DD> Windows_NT 30 # <DT> PATH <DD> F:\Anaconda3\Library\bin;F:\Anaconda3\DLLs;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\iCLS\;C:\Program Files\Intel\Intel(R) Management Engine Components\iCLS\;C:\windows\system32;C:\windows;C:\windows\System32\Wbem;C:\windows\System32\WindowsPowerShell\v1.0\;C:\windows\System32\OpenSSH\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;F:\Python35\Scripts;C:\Users\劉永峯\AppData\Local\Microsoft\WindowsApps; 31 # <DT> PATHEXT <DD> .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC 32 # <DT> PROCESSOR_ARCHITECTURE <DD> AMD64 33 # <DT> PROCESSOR_IDENTIFIER <DD> Intel64 Family 6 Model 92 Stepping 9, GenuineIntel 34 # <DT> PROCESSOR_LEVEL <DD> 6 35 # <DT> PROCESSOR_REVISION <DD> 5c09 36 # <DT> PROGRAMDATA <DD> C:\ProgramData 37 # <DT> PROGRAMFILES <DD> C:\Program Files 38 # <DT> PROGRAMFILES(X86) <DD> C:\Program Files (x86) 39 # <DT> PROGRAMW6432 <DD> C:\Program Files 40 # <DT> PSMODULEPATH <DD> C:\Program Files\WindowsPowerShell\Modules;C:\windows\system32\WindowsPowerShell\v1.0\Modules 41 # <DT> PUBLIC <DD> C:\Users\Public 42 # <DT> PYCHARM_HOSTED <DD> 1 43 # <DT> PYCHARM_MATPLOTLIB_PORT <DD> 50202 44 # <DT> PYTHONIOENCODING <DD> UTF-8 45 # <DT> PYTHONPATH <DD> C:\PyCharm 2017.3.3\helpers\pycharm_matplotlib_backend;D:\Python\零基礎學 python 46 # <DT> PYTHONUNBUFFERED <DD> 1 47 # <DT> SESSIONNAME <DD> Console 48 # <DT> SYSTEMDRIVE <DD> C: 49 # <DT> SYSTEMROOT <DD> C:\windows 50 # <DT> TEMP <DD> C:\Users\劉永峯\AppData\Local\Temp 51 # <DT> TMP <DD> C:\Users\劉永峯\AppData\Local\Temp 52 # <DT> USERDOMAIN <DD> LAPTOP-PJ9B1NQR 53 # <DT> USERDOMAIN_ROAMINGPROFILE <DD> LAPTOP-PJ9B1NQR 54 # <DT> USERNAME <DD> 劉永峯 55 # <DT> USERPROFILE <DD> C:\Users\劉永峯 56 # <DT> WINDIR <DD> C:\windows 57 # </DL>
| 環境變量 | 含 義 | 環境變量 | 含 義 |
| REMOTE_ADDR | 服務器的地址 | SCRIPT_NAME | 服務器執行腳本名字 |
| PATH_INFO | 路徑信息 | HTTP_USER_AGENT | 客戶端軟件 |
| REQUEST_METHOD | 客戶端請求的方法，能夠爲GET或POST | SERVER_PROTOCOL | 服務器支持協議 |
| SERVER_NAME | 服務器名字 | SERVER_SOFTWARE | 服務器端軟件信息 |
| SERVER_PORT | 服務器端口 | QUERY_STRING | 查詢字符串 |
13.3.3 解析用戶的輸入
1 #！E：/Python3/python.exe 2 print ("Content-Type:text/html\n\n") 3 import cgi 4 form = cgi.FieldStorage() 5 for key in form.keys(): 6 print (key, "==>", form[key].value) 7 print ("<br/>")
1 #！E：/Python3/python.exe 2 print ("Content-Type:text/html\n\n") 3 import cgi 4 form = cgi.FieldStorage() 5 for key in form.keys(): 6 print (key, "==>", form.getlist(key)) 7 print ("<br/>")
1 #！E：/Python3/python.exe 2 print ("Content-Type:text/html\n\n") 3 import cgi 4 form = cgi.FieldStorage() 5 for key in form.keys(): 6 for value in form.getlist(key): 7 print (key, "==>", cgi.escape(value)) 8 print ("<br/>")
13.4 獲取HTML資源
13.4.1 使用urlopen和urlretrieve獲取HTTP資源
1 from urllib.request import urlopen 2 r = urlopen("http://www.python.org") 3 print (r.read()) 4 # 輸出：b'<!doctype html>\n<!--[if lt IE 7]> 5 # <html class="no-js ie6 lt-ie7 lt-ie8 lt-ie9"> 6 # <![endif]-->\n<!--[if IE 7]> 7 # <html class="no-js ie7 lt-ie8 lt-ie9"> 8 # <![endif]-->\n<!--[if IE 8]> 9 # <html class="no-js ie8 lt-ie9"> 10 # <![endif]-->\n<!--[if gt IE 8]><!--><html class="no-js" lang="en" dir="ltr"> 11 # <!--<![endif]-->\n\n<head>\n 12 # <meta charset="utf-8">\n 13 # <meta http-equiv="X-UA-Compatible" content="IE=edge">\n\n 14 # <link rel="prefetch" href="//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js">\n\n 15 # <meta name="application-name" content="Python.org">\n 16 # <meta name="msapplication-tooltip" content="The official home of the 17 # Python Programming Language">\n <meta name="apple-mobile-web-app-title" 18 # content="Python.org">\n <meta name="apple-mobile-web-app-capable" content="yes">\n 19 # <meta name="apple-mobile-web-app-status-bar-style" content="black">\n\n 20 # <meta name="viewport" content="width=device-width, initial-scale=1.0">\n 21 # <meta name="HandheldFriendly" content="True">\n 22 # <meta name="format-detection" content="telephone=no">\n 23 # <meta http-equiv="cleartype" content="on">\n 24 # <meta http-equiv="imagetoolbar" content="false">\n\n 25 # <script src="/static/js/libs/modernizr.js"></script>\n\n 26 # <link href="/static/stylesheets/style.css" rel="stylesheet" 27 # type="text/css" title="default" />\n 28 # <link href="/static/stylesheets/mq.css" rel="stylesheet" 29 # type="text/css" media="not print, braille, embossed, speech, tty" />\n 30 # \n\n <!--[if (lte IE 8)&(!IEMobile)]>\n 31 # <link href="/static/stylesheets/no-mq.css" 32 # rel="stylesheet" type="text/css" media="screen" />\n \n 33 # \n <![endif]-->\n\n \n 34 # <link rel="icon" type="image/x-icon" href="/static/favicon.ico">\n 35 # <link rel="apple-touch-icon-precomposed" sizes="144x144" 36 # href="/static/apple-touch-icon-144x144-precomposed.png">\n 37 # <link rel="apple-touch-icon-precomposed" sizes="114x114" 38 # href="/static/apple-touch-icon-114x114-precomposed.png">\n 39 # <link rel="apple-touch-icon-precomposed" 40 # sizes="72x72" href="/static/apple-touch-icon-72x72-precomposed.png">\n 41 # <link rel="apple-touch-icon-precomposed" href="/static/apple-touch-icon-precomposed.png">\n 42 # <link rel="apple-touch-icon" href="/static/apple-touch-icon-precomposed.png">\n\n 43 # \n <meta name="msapplication-TileImage" 44 # content="/static/metro-icon-144x144-precomposed.png"><!-- white shape -->\n 45 # <meta name="msapplication-TileColor" content="#3673a5"><!-- python blue -->\n 46 # <meta name="msapplication-navbutton-color" content="#3673a5">\n\n 47 # <title>Welcome to Python.org</title>\n\n 48 # <meta name="description" content="The official home of the Python Programming Language">\n 49 # <meta name="keywords" content="Python programming language object 50 # oriented web free open source software license documentation download community">\n\n 51 # \n <meta property="og:type" content="website">\n 52 # <meta property="og:site_name" content="Python.org">\n 53 # <meta property="og:title" content="Welcome to Python.org">\n 54 # <meta property="og:description" content="The official home of the Python 55 # Programming Language">\n \n <meta property="og:image" 56 # content="https://www.python.org/static/opengraph-icon-200x200.png">\n 57 # <meta property="og:image:secure_url" 58 # content="https://www.python.org/static/opengraph-icon-200x200.png">\n \n 59 # <meta property="og:url" content="https://www.python.org/">\n\n 60 # <link rel="author" href="/static/humans.txt">\n\n 61 # <link rel="alternate" type="application/rss+xml" title="Python Enhancement Proposals"\n 62 # href="https://www.python.org/dev/peps/peps.rss/">\n 63 # <link rel="alternate" type="application/rss+xml" title="Python Job Opportunities"\n 64 # href="https://www.python.org/jobs/feed/rss/">\n 65 # <link rel="alternate" type="application/rss+xml" title="Python Software Foundation News"\n 66 # href="https://feeds.feedburner.com/PythonSoftwareFoundationNews">\n 67 # <link rel="alternate" type="application/rss+xml" title="Python Insider"\n 68 # href="https://feeds.feedburner.com/PythonInsider">\n\n \n\n \n 69 # <script type="application/ld+json">\n {\n "@context": "http://schema.org",\n 70 # "@type": "WebSite",\n "url": "https://www.python.org/",\n 71 # "potentialAction": {\n "@type": "SearchAction",\n "target": "https://www.python.org/search/?q={search_term_string}",\n "query-input": "required name=search_term_string"\n }\n }\n </script>\n\n \n <script type="text/javascript">\n var _gaq = _gaq || [];\n _gaq.push([\'_setAccount\', \'UA-39055973-1\']);\n _gaq.push([\'_trackPageview\']);\n\n (function() {\n var ga = document.createElement(\'script\'); ga.type = \'text/javascript\'; ga.async = true;\n ga.src = (\'https:\' == document.location.protocol ? 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href="/events/" title="" class="">Events</a>\n \n \n\n<ul class="subnav menu" role="menu" aria-hidden="true">\n \n <li class="tier-2 element-1" role="treeitem"><a href="/events/python-events" title="">Python Events</a></li>\n \n <li class="tier-2 element-2" role="treeitem"><a href="/events/python-user-group/" title="">User Group Events</a></li>\n \n <li class="tier-2 element-3" role="treeitem"><a href="/events/python-events/past/" title="">Python Events Archive</a></li>\n \n <li class="tier-2 element-4" role="treeitem"><a href="/events/python-user-group/past/" title="">User Group Events Archive</a></li>\n \n <li class="tier-2 element-5" role="treeitem"><a href="https://wiki.python.org/moin/PythonEventsCalendar#Submitting_an_Event" title="">Submit an Event</a></li>\n \n</ul>\n\n \n </li>\n \n \n \n \n \n</ul>\n\n \n </nav>\n\n <div class="header-banner "> <!-- for optional "do-not-print" class -->\n \n <div id="dive-into-python" class="flex-slideshow slideshow">\n\n <ul class="launch-shell menu" id="launch-shell">\n <li>\n <a class="button prompt" id="start-shell" data-shell-container="#dive-into-python" href="/shell/">>_\n <span class="message">Launch Interactive Shell</span>\n </a>\n </li>\n </ul>\n\n <ul class="slides menu">\n \n <li>\n <div class="slide-code"><pre><code><span class="comment"># Python 3: Fibonacci series up to n</span>\r\n>>> def fib(n):\r\n>>> a, b = 0, 1\r\n>>> while a < n:\r\n>>> print(a, end=\' \')\r\n>>> a, b = b, a+b\r\n>>> print()\r\n>>> fib(1000)\r\n<span class="output">0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987</span></code></pre></div>\n <div class="slide-copy"><h1>Functions Defined</h1>\r\n<p>The core of extensible programming is defining functions. Python allows mandatory and optional arguments, keyword arguments, and even arbitrary argument lists. <a href="//docs.python.org/3/tutorial/controlflow.html#defining-functions">More about defining functions in Python 3</a></p></div>\n </li>\n \n <li>\n <div class="slide-code"><pre><code><span class="comment"># Python 3: List comprehensions</span>\r\n>>> fruits = [\'Banana\', \'Apple\', \'Lime\']\r\n>>> loud_fruits = [fruit.upper() for fruit in fruits]\r\n>>> print(loud_fruits)\r\n<span class="output">[\'BANANA\', \'APPLE\', \'LIME\']</span>\r\n\r\n<span class="comment"># List and the enumerate function</span>\r\n>>> list(enumerate(fruits))\r\n<span class="output">[(0, \'Banana\'), (1, \'Apple\'), (2, \'Lime\')]</span></code></pre></div>\n <div class="slide-copy"><h1>Compound Data Types</h1>\r\n<p>Lists (known as arrays in other languages) are one of the compound data types that Python understands. Lists can be indexed, sliced and manipulated with other built-in functions. <a href="//docs.python.org/3/tutorial/introduction.html#lists">More about lists in Python 3</a></p></div>\n </li>\n \n <li>\n <div class="slide-code"><pre><code><span class="comment"># Python 3: Simple arithmetic</span>\r\n>>> 1 / 2\r\n<span class="output">0.5</span>\r\n>>> 2 ** 3\r\n<span class="output">8</span>\r\n>>> 17 / 3 <span class="comment"># classic division returns a float</span>\r\n<span class="output">5.666666666666667</span>\r\n>>> 17 // 3 <span class="comment"># floor division</span>\r\n<span class="output">5</span></code></pre></div>\n <div class="slide-copy"><h1>Intuitive Interpretation</h1>\r\n<p>Calculations are simple with Python, and expression syntax is straightforward: the operators <code>+</code>, <code>-</code>, <code>*</code> and <code>/</code> work as expected; parentheses <code>()</code> can be used for grouping. <a href="http://docs.python.org/3/tutorial/introduction.html#using-python-as-a-calculator">More about simple math functions in Python 3</a>.</p></div>\n </li>\n \n <li>\n <div class="slide-code"><pre><code><span class="comment"># Python 3: Simple output (with Unicode)</span>\r\n>>> print("Hello, I\'m Python!")\r\n<span class="output">Hello, I\'m Python!</span>\r\n\r\n<span class="comment"># Input, assignment</span>\r\n>>> name = input(\'What is your name?\\n\')\r\n>>> print(\'Hi, %s.\' % name)\r\n<span class="output">What is your name?\r\nPython\r\nHi, Python.</span></code></pre></div>\n <div class="slide-copy"><h1>Quick & Easy to Learn</h1>\r\n<p>Experienced programmers in any other language can pick up Python very quickly, and beginners find the clean syntax and indentation structure easy to learn. <a href="//docs.python.org/3/tutorial/">Whet your appetite</a> with our Python 3 overview.</p>\r\n </div>\n </li>\n \n <li>\n <div class="slide-code"><pre><code><span class="comment"># For loop on a list</span>\r\n>>> numbers = [2, 4, 6, 8]\r\n>>> product = 1\r\n>>> for number in numbers:\r\n... product = product * number\r\n... \r\n>>> print(\'The product is:\', product)\r\n<span class="output">The product is: 384</span></code></pre></div>\n <div class="slide-copy"><h1>All the Flow You’d Expect</h1>\r\n<p>Python knows the usual control flow statements that other languages speak — <code>if</code>, <code>for</code>, <code>while</code> and <code>range</code> — with some of its own twists, of course. <a href="//docs.python.org/3/tutorial/controlflow.html">More control flow tools in Python 3</a></p></div>\n </li>\n \n </ul>\n </div>\n\n\n </div>\n\n \n <div class="introduction">\n <p>Python is a programming language that lets you work quickly <span class="breaker"></span>and integrate systems more effectively. <a class="readmore" href="/doc/">Learn More</a></p>\n </div>\n\n\n </div><!-- end .container -->\n </header>\n\n <div id="content" class="content-wrapper">\n <!-- Main Content Column -->\n <div class="container">\n\n <section class="main-content " role="main">\n\n \n \n\n \n\n \n\n <div class="row">\n\n <div class="small-widget get-started-widget">\n <h2 class="widget-title"><span aria-hidden="true" class="icon-get-started"></span>Get Started</h2>\r\n<p>Whether you\'re new to programming or an experienced developer, it\'s easy to learn and use Python.</p>\r\n<p><a href="/about/gettingstarted/">Start with our Beginner’s Guide</a></p>\n </div>\n\n <div class="small-widget download-widget">\n <h2 class="widget-title"><span aria-hidden="true" class="icon-download"></span>Download</h2>\n<p>Python source code and installers are available for download for all versions!</p>\n<p>Latest: <a href="/downloads/release/python-372/">Python 3.7.2</a></p>\n </div>\n\n <div class="small-widget documentation-widget">\n <h2 class="widget-title"><span aria-hidden="true" class="icon-documentation"></span>Docs</h2>\r\n<p>Documentation for Python\'s standard library, along with tutorials and guides, are available online.</p>\r\n<p><a href="https://docs.python.org">docs.python.org</a></p>\n </div>\n\n <div class="small-widget jobs-widget last">\n <h2 class="widget-title"><span aria-hidden="true" class="icon-jobs"></span>Jobs</h2>\r\n<p>Looking for work or have a Python related position that you\'re trying to hire for? Our <strong>relaunched community-run job board</strong> is the place to go.</p>\r\n<p><a href="//jobs.python.org">jobs.python.org</a></p>\n </div>\n\n </div>\n\n <div class="list-widgets row">\n\n <div class="medium-widget blog-widget">\n \n <div class="shrubbery">\n \n <h2 class="widget-title"><span aria-hidden="true" class="icon-news"></span>Latest News</h2>\n <p class="give-me-more"><a href="http://blog.python.org" title="More News">More</a></p>\n \n <ul class="menu">\n \n \n <li>\n<time datetime="2018-12-24T11:26:00+00:00"><span class="say-no-more">2018-</span>12-24</time>\n <a href="http://feedproxy.google.com/~r/PythonInsider/~3/KoVsY316T7U/python-372-and-368-are-now-available.html">Python 3.7.2 and 3.6.8 are now available. Python 3.7.2 is the next maintenance release ...</a></li>\n \n <li>\n<time datetime="2018-12-24T11:26:00+00:00"><span class="say-no-more">2018-</span>12-24</time>\n <a href="http://feedproxy.google.com/~r/PythonInsider/~3/o5ROzg9M8NY/python-372-and-368-are-now-available.html">Python 3.7.2 and 3.6.8 are now available. Python 3.7.2 is the next maintenance release ...</a></li>\n \n <li>\n<time datetime="2018-12-20T17:55:00.000003+00:00"><span class="say-no-more">2018-</span>12-20</time>\n <a href="http://feedproxy.google.com/~r/PythonSoftwareFoundationNews/~3/UJLhXUl_Le8/upcoming-pypi-improvements-for-2019.html">The Python Package Index (PyPI) is far and away the ...</a></li>\n \n <li>\n<time datetime="2018-12-19T19:11:00.000002+00:00"><span class="say-no-more">2018-</span>12-19</time>\n <a href="http://feedproxy.google.com/~r/PythonSoftwareFoundationNews/~3/HPqp93-tF3M/pypi-security-and-accessibility-q1-2019.html">Earlier this year we launched a Request for Information (RFI) ...</a></li>\n \n <li>\n<time datetime="2018-12-17T11:30:00+00:00"><span class="say-no-more">2018-</span>12-17</time>\n <a href="http://feedproxy.google.com/~r/PythonSoftwareFoundationNews/~3/oAgPaokjjg4/evangelizing-python-in-africa-chukwudi_65.html">p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px \'Helvetica Neue\'; ...</a></li>\n \n </ul>\n </div><!-- end .shrubbery -->\n\n </div>\n\n <div class="medium-widget event-widget last">\n \n <div class="shrubbery">\n \n <h2 class="widget-title"><span aria-hidden="true" class="icon-calendar"></span>Upcoming Events</h2>\n <p class="give-me-more"><a href="/events/calendars/" title="More Events">More</a></p>\n \n <ul class="menu">\n \n \n \n <li>\n<time datetime="2019-02-02T00:00:00+00:00"><span class="say-no-more">2019-</span>02-02</time>\n <a href="/events/python-events/800/">FOSDEM 2019</a></li>\n \n \n \n <li>\n<time datetime="2019-02-09T00:00:00+00:00"><span class="say-no-more">2019-</span>02-09</time>\n <a href="/events/python-user-group/803/">DjangoGirls Bangalore</a></li>\n \n \n \n <li>\n<time datetime="2019-02-09T00:00:00+00:00"><span class="say-no-more">2019-</span>02-09</time>\n <a href="/events/python-events/770/">PyTennessee 2019</a></li>\n \n \n \n <li>\n<time datetime="2019-02-15T00:00:00+00:00"><span 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width="100%" class="quote-from">\n <tbody>\n <tr>\n \n <td><p><a href="/success-stories/using-python-to-automate-tedious-tasks/">Using Python to Automate Tedious Tasks</a> <em>by Nat Dunn</em></p></td>\n </tr>\n </tbody>\n </table>\n </div>\n \n\n </div><!-- end .shrubbery -->\n\n </div>\n\n <div class="medium-widget applications-widget last">\n <div class="shrubbery">\n <h2 class="widget-title"><span aria-hidden="true" class="icon-python"></span>Use Python for…</h2>\r\n<p class="give-me-more"><a href="/about/apps" title="More Applications">More</a></p>\r\n\r\n<ul class="menu">\r\n <li><b>Web Development</b>:\r\n <span class="tag-wrapper"><a class="tag" href="http://www.djangoproject.com/">Django</a>, <a class="tag" href="http://www.pylonsproject.org/">Pyramid</a>, <a class="tag" href="http://bottlepy.org">Bottle</a>, <a class="tag" href="http://tornadoweb.org">Tornado</a>, <a href="http://flask.pocoo.org/" class="tag">Flask</a>, <a class="tag" href="http://www.web2py.com/">web2py</a></span></li>\r\n <li><b>GUI Development</b>:\r\n <span class="tag-wrapper"><a class="tag" href="http://wiki.python.org/moin/TkInter">tkInter</a>, <a class="tag" href="https://wiki.gnome.org/Projects/PyGObject">PyGObject</a>, <a class="tag" href="http://www.riverbankcomputing.co.uk/software/pyqt/intro">PyQt</a>, <a class="tag" href="https://wiki.qt.io/PySide">PySide</a>, <a class="tag" href="https://kivy.org/">Kivy</a>, <a class="tag" href="http://www.wxpython.org/">wxPython</a></span></li>\r\n <li><b>Scientific and Numeric</b>:\r\n <span class="tag-wrapper">\r\n<a class="tag" href="http://www.scipy.org">SciPy</a>, <a class="tag" href="http://pandas.pydata.org/">Pandas</a>, <a href="http://ipython.org" class="tag">IPython</a></span></li>\r\n <li><b>Software Development</b>:\r\n <span class="tag-wrapper"><a class="tag" href="http://buildbot.net/">Buildbot</a>, <a class="tag" href="http://trac.edgewall.org/">Trac</a>, <a class="tag" href="http://roundup.sourceforge.net/">Roundup</a></span></li>\r\n <li><b>System Administration</b>:\r\n <span class="tag-wrapper"><a class="tag" href="http://www.ansible.com">Ansible</a>, <a class="tag" href="http://www.saltstack.com">Salt</a>, <a class="tag" href="https://www.openstack.org">OpenStack</a></span></li>\r\n</ul>\r\n\n </div><!-- end .shrubbery -->\n </div>\n\n </div>\n\n \n <div class="pep-widget">\n\n <h2 class="widget-title">\n <span class="prompt">>>></span> <a href="/dev/peps/">Python Enhancement Proposals<span class="say-no-more"> (PEPs)</span></a>: The future of Python<span class="say-no-more"> is discussed here.</span>\n <a aria-hidden="true" class="rss-link" href="/dev/peps/peps.rss"><span class="icon-feed"></span> RSS</a>\n </h2>\n\n\n \n \n </div>\n\n <div class="psf-widget">\n\n <div class="python-logo"></div>\n \n <h2 class="widget-title">\r\n <span class="prompt">>>></span> <a href="/psf/">Python Software Foundation</a>\r\n</h2>\r\n<p>The mission of the 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1 from urllib.request import urlopen 2 fp = urlopen("http://www.python.org") 3 op = open("python.html","wb") 4 n = 0 5 while True: 6 s = fp.read(1024) 7 if not s: 8 break 9 op.write(s) 10 n = n + len(s) 11 fp.close() 12 op.close() 13 print ("retrieved", n, "bytes from", fp.url)
1) 使用代理
2) 直接保存URL資源
1 from urllib.request import urlretrieve 2 filename, m = urlretrieve("http://www.baidu.com") 3 filename 4 filename, m = urlretrieve("http://www.baidu.com", filename="I:/book/source/html/baidu.html") 5 filename
1 from urllib.request import urlretrieve 2 def reporthook(block_count, block_size, file_size): 3 if file_size == -1: 4 print ("retrieved data", "block_count * bolck_size") 5 else: 6 print ("retrieved data", "block_count * bolck_size", "/", "file_size") 7 urlretrieve("file:///I:/book/source/html/python.html", filename="", reporthook=reporthook) 8 retrieve data 0 / 16578 9 retrieve data 8192 / 16578 10 retrieve data 16384 / 16578 11 retrieve data 24576 / 16578 12 urlretrieve("http://www.python.org", filename="", reporthook=reporthook) 13 retrieve data 0 / 16578 14 retrieve data 8192 / 16578 15 retrieve data 16384 / 16578 16 retrieve data 24576 / 16578 17 urlretrieve("http://www.google.com", filename="", reporthook=reporthook) 18 retrieve datad 0 19 retrieve datad 8192
1 def download(url, filename=""): 2 def reporthook(block_count, block_size, file_size): 3 if file_size == -1: 4 print("Can't determine the file size, now retrieved", block_count*block_size) 5 else: 6 percentage = int((block_count*block_size*100.0)/file_size) 7 if percentage > 100: 8 print("100%") 9 else: 10 print("%d%%" % (percentage)) 11 filehandler, m = urlretrieve(url, filename, reporthook=reporthook) 12 print("Done") 13 return filehandler
13.4.2 分析返回資源的相關信息
1 from urllib.request import urlopen 2 r = urlopen("http://baidu.com") 3 print(r.geturl()) 4 print(r.url) 5 # 輸出：http://baidu.com 6 # http://baidu.com
1 from urllib.request import urlopen 2 r = urlopen("http://baidu.com") 3 m = r.info() 4 m.get_countent_type() 5 m.get_countent_maintype() 6 m.get_countent_subtype() 7 print(m)
1 from urllib.request import urlopen 2 r = urlopen("http://baidu.com") 3 m = r.info() 4 m.get_countent_type() 5 m.get_countent_maintype() 6 m.get_countent_subtype() 7 m 8 for k,v in r.info().items(): 9 print (k, "=", v) 10 r.headers
13.4.3 自定義獲取資源方式
1）訪問須要簡單認證的URL資源
1 def prompt_user_passwd(self, host, realm): 2 """Override this in a GUI environment!""" 3 import getpass 4 try: 5 user = input("Enter username for %s at %s:" % (realm, host)) 6 passwd = getpass.getpass("Enter password for %s in %s at %s:" % (user, realm, host)) 7 return user, passwd 8 except KeyboardInterrupt: 9 print() 10 return None, None
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