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python网络编程学习笔记（三）

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python网络编程学习笔记（三）

python网络编程基础，第四版
pycharm实现，python版本2.7.5

第二部分web Service
二、解析html和xhtml

第七章 解析Html 和XHtml p151-p168
1.提取标题
代码：

#coding=utf-8
from HTMLParser import HTMLParser
import sys

class TitleParser(HTMLParser):
    def __init__(self):
        self.title=''
        self.readingtitle=0
        HTMLParser.__init__(self)

    def handle_starttag(self, tag, attrs):
        if tag =='title':
            self.readingtitle = 1

    def handle_data(self, data):
        if self.readingtitle:
            self.title += data

    def handle_endtag(self, tag):
        if tag == 'title':
            self.readingtitle = 0

    def gettitle(self):
        return self.title

fd = open(sys.argv[1])
tp = TitleParser()
tp.feed(fd.read())
print "Title is:",tp.gettitle()

运行结果：

D:\python\python.exe E:/code/python/unit7/basic_title.py
E:/code/python/unit7/faqs.html
Title is: Appendix?B. MySQL 5.6 Frequently Asked Questions

Process finished with exit code 0

注：从表中摘取数据，<TR>或<TD>

2.改进
代码：

#coding=utf-8
from HTMLParser import HTMLParser
from htmlentitydefs import entitydefs
import sys

class TitleParser(HTMLParser):
    def __init__(self):
        self.title=''
        self.readingtitle=0
        HTMLParser.__init__(self)

    def handle_starttag(self, tag, attrs):
        if tag =='title':
            self.readingtitle = 1

    def handle_data(self, data):
        if self.readingtitle:
            self.title += data

    def handle_endtag(self, tag):
        if tag == 'title':
            self.readingtitle = 0
    def handle_entityref(self, name):
        if entitydefs.has_key(name):
            self.handle_data(entitydefs[name])
        else:
            self.handle_data('&'+name+';')

    def gettitle(self):
        return self.title

fd = open(sys.argv[1])
tp = TitleParser()
tp.feed(fd.read())
print "Title is:",tp.gettitle()

etitle.html

<!DOCTYPE html>
<html >
<head>
    <title>Document Title &Intro</title>
</head>
<body>
this is my text.
</body>
</html>

运行结果一：

D:\python\python.exe E:/code/python/unit7/basic_title.py
E:/code/python/unit7/etitle.html
Title is: Document Title Intro

Process finished with exit code 0
运行结果二：

D:\python\python.exe E:/code/python/unit7/etitle.py
E:/code/python/unit7/etitle.html
Title is: Document Title &Intro

Process finished with exit code 0

当一个实体出现时，代码检查该实体是否可以识别，可以，转换为相应得知，否则输入流中的文字；

3.转换字符参考
代码：

#coding=utf-8
from HTMLParser import HTMLParser
from htmlentitydefs import entitydefs
import sys

class TitleParser(HTMLParser):
    def __init__(self):
        self.title=''
        self.readingtitle=0
        HTMLParser.__init__(self)

    def handle_starttag(self, tag, attrs):
        if tag =='title':
            self.readingtitle = 1

    def handle_data(self, data):
        if self.readingtitle:
            self.title += data

    def handle_endtag(self, tag):
        if tag == 'title':
            self.readingtitle = 0
    def handle_entityref(self, name):
        if entitydefs.has_key(name):
            self.handle_data(entitydefs[name])
        else:
            self.handle_data('&'+name+';')
    def handle_charref(self, name):
        try:
            charnum=int(name)
        except ValueError:
            return
        if charnum<1 or charnum>225:
            return
        self.handle_data(chr(charnum))

    def gettitle(self):
        return self.title

fd = open(sys.argv[1])
tp = TitleParser()
tp.feed(fd.read())
print "Title is:",tp.gettitle()

4.处理不均衡的标签
代码：

#coding=utf-8
from HTMLParser import HTMLParser
from htmlentitydefs import entitydefs
import sys,re

class TitleParser(HTMLParser):
    def __init__(self):
        self.taglevels=[]
        self.handledtags=['title','ul','li']
        self.processing=None
        HTMLParser.__init__(self)

    def handle_starttag(self, tag, attrs):
        if len(self.taglevels) and self.taglevels[-1] == tag:
            self.handle_endtag(tag)

        self.taglevels.append(tag)
        if tag in self.handledtags:
            self.data = ''
            self.processing = tag
            if tag == 'ul':
                print"List start"

    def handle_data(self, data):
        if self.processing:
            self.data += data

    def handle_endtag(self, tag):
        if not tag in self.taglevels:
            return

        while len(self.taglevels):
            starttag = self.taglevels.pop()

            if starttag in self.handledtags:
                self.finishprocessing(starttag)

            if starttag == tag:
                break

    def cleanse(self):
        self.data = re.sub('\s+', ' ', self.data)

    def finishprocessing(self, tag):
        self.cleanse()
        if tag == 'title' and tag == self.processing:
            print "Dom title", self.data
        elif tag == 'ul':
            print "List ended"
        elif tag == 'li' and tag == self.processing:
            print "List item", self.data
        self.processing = None

    def gettitle(self):
        return self.title

处理特殊值，如果在映射表中有对应的，即采用映射的值，否则为字面值

 def handle_entityref(self, name):
        if entitydefs.has_key(name):
            self.handle_data(entitydefs[name])
        else:
            self.handle_data('&' + name + ';')

    def handle_charref(self, name):
        try:
            charnum = int(name)
        except ValueError:
            return

        if charnum < 1 or charnum > 255:
            return

        self.handle_data(chr(charnum))

fd = open(sys.argv[1])
tp = TitleParser()
tp.feed(fd.read())

运行结果：

D:\python\python.exe E:/code/python/unit7/4un.py
E:/code/python/unit7/4un.html
Dom title DOCTYPE Title & Intro?
List start
List item First List item
List item second list item
List item second list item
List ended

Process finished with exit code 0

5.一个可以实际工作的例子

三、XML和XML-RPC

P169-p190
展示XML文档：tree,event.基于事件的解析器可以扫描文档，事件解析器可以响应。
8.2 使用Dom
代码：

#coding=utf-8
from xml.dom import minidom,Node

def scanNode(node,level=0):
    msg = node.__class__.__name__
    if node.nodeType == Node.ELEMENT_NODE:
        msg += ",tag" + node.tagName
    print " " * level * 4, msg
    if node.hasChildNodes:
        for child in node.childNodes:
            scanNode(child, level + 1)

doc = minidom.parse("Sample.xml")
scanNode(doc)

运行结果：

D:\python\python.exe E:/code/python/unit8/un1.py

 Document
>      Element,tagbook
>          Text
>          Element,tagtitle
>              Text
>          Text
>          Element,tagauthor
>              Text
>              Element,tagname
>                  Text
>                  Element,tagfirst
>                      Text
>                  Text
>                  Element,taglast
>                      Text
>                  Text
>              Text
>              Element,tagaffiliation
>                  Text
>              Text
>          Text
>          Element,tagchapter
>              Text
>              Element,tagtitle
>                  Text
>              Text
>              Element,tagpara
>                  Text
>                  Element,tagcompany
>                      Text
>                  Text
>              Text
>          Text

Process finished with exit code 0

sample.xml

<?xml version="1.0" encoding="UTF-8"?>
<book>
    <title> Sample XML Thing </title>
    <author>
        <name>
            <first>Benjamin</first>
            <last>Smith</last>
        </name>
        <affiliation>Springy Widgets,Inc.</affiliation>
    </author>

    <chapter number = "1">
        <title>First chapter</title>
        <para>
            I think widgets are great.you should buy lots
            of them from <company>Springy widgets,Inc</company>
        </para>
    </chapter>
</book>

2.使用dom完全解析
代码：

#coding=utf-8
"""
将XML以文本形式重新格式化输出
1.使用Node的节点类型,判断下一步如何处理
2.对不同的节点名(tagName)进行相应的处理
"""
from xml.dom import minidom, Node
import re, textwrap

class SampleScanner:
    def __init__(self, doc):
        for child in doc.childNodes:
            if child.nodeType == Node.ELEMENT_NODE and child.tagName == "book":
                """只处理book元素"""
                self.handleBook(child)

    def gettext(self, nodelist):
        """获取当前节点的文本,
        1.如果当前的节点为TEXT_NODE,将文本追加到列表中
        2.如果当前的节点不是TEXT_NODE,递归地调用gettext"""
        retlist = []
        for node in nodelist:
            if node.nodeType == Node.TEXT_NODE:
                retlist.append(node.wholeText)
            elif node.hasChildNodes:
                retlist.append(self.gettext(node.childNodes))

        return re.sub("\s+", " ", "".join(retlist))

    def handleBook(self, node):
        """处理Book节点
        1.如果不是ELEMENT_NODE,不予理睬
        2.如果是title,直接打印出文本内容
        3.如果是author,调用handleAuthor,继续处理节点
        4.如果是chapter,调用handleChapter,继续处理节点
        """
        for child in node.childNodes:
            if child.nodeType != Node.ELEMENT_NODE:
                continue
            if child.tagName == "title":
                print "Book title is :", self.gettext(child.childNodes)
            if child.tagName == "author":
                self.handleAuthor(child)
            if child.tagName == "chapter":
                self.handleChapter(child)

    def handleAuthor(self, node):
        """处理Autho节点
        1.如果不是ELEMENT_NODE,不予理睬
        2.如果是name,调用handleAuthoerName,继续处理节点
        3.如果是affiliation,调用gettext,并打印出来
        """
        for child in node.childNodes:
            if child.nodeType != Node.ELEMENT_NODE:
                continue
            if child.tagName == "name":
                self.handleAuthorName(child)
            elif child.tagName == "affiliation":
                print "Author affiliation:", self.gettext([child])

    def handleAuthorName(self, node):
        """处理author.name节点
        1.使用getElementsByTagName获得子节点
        2.调用gettext得到子节点的文本,并打印处理
        """
        surname = self.gettext(node.getElementsByTagName("last"))
        givenname = self.gettext(node.getElementsByTagName("first"))

        print "Author Name:%s %s " % (surname, givenname)

    def handleChapter(self, node):
        """处理chapter节点
        1.如果不是ELEMENT_NODE,不予理睬
        2.如果是para,调用handlePara,继续处理
        """
        print "*** Start of Chapter %s,%s" % (
        node.getAttribute("number"), self.gettext(node.getElementsByTagName("title")))

        for child in node.childNodes:
            if child.nodeType != Node.ELEMENT_NODE:
                continue
            if child.tagName == "para":
                self.handlePara(child)

    def handlePara(self, node):
        """
        1.获取当前节点的文本
        2.调用textwrap格式化文本
        """
        paratext = self.gettext([node])
        paratext = textwrap.fill(paratext)
        print paratext

doc = minidom.parse("Sample.xml")
SampleScanner(doc)

运行结果：

D:\python\python.exe E:/code/python/unit8/un2.py
Book title is : Sample XML Thing
Author Name:Smith Benjamin
Author affiliation: Springy Widgets,Inc.
*** Start of Chapter 1,First chapter
I think widgets are great.you should buy lots of them from Springy
widgets,Inc

Process finished with exit code 0

3.使用Dom产生文档
代码：

#coding=utf-8
"""
使用minidom生成XML
1.创建Element,createElement
2.添加子节点,appendChild
3.创建Text,createTextNode
4.创建属性,createAttribute
"""
from xml.dom import minidom,Node

# 创建Document
doc = minidom.Document()
# 创建book节点
book = doc.createElement("book")
doc.appendChild(book)
# 创建Title节点
title = doc.createElement("title")
text = doc.createTextNode("Sample XML Thing")
title.appendChild(text)
book.appendChild(title)
# 创建author节点
author = doc.createElement("author")
# 创建name节点
name = doc.createElement("name")
first = doc.createElement("first")
first.appendChild(doc.createTextNode("Benjamin"))
name.appendChild(first)

last = doc.createElement("last")
last.appendChild(doc.createTextNode("Smith"))
name.appendChild(last)

author.appendChild(name)
book.appendChild(author)
# author节点完毕

# 创建chapter节点
chapter = doc.createElement("chapter")
chapter.setAttribute("number","1")
title = doc.createElement("title")
title.appendChild(doc.createTextNode("Fisrt Chapter"))
chapter.appendChild(title)

para = doc.createElement("para")
para.appendChild(doc.createTextNode("I think widgets are great.you should buy lots \
of them from"))
company = doc.createElement("company")
company.appendChild(doc.createTextNode("Springy widgets,Inc"))
para.appendChild(company)

chapter.appendChild(para)
# chapter节点完毕
book.appendChild(chapter)
# book节点完毕

print doc.toprettyxml(indent = " ")

运行结果：

D:\python\python.exe E:/code/python/unit8/un3.py

<?xml version="1.0" ?>
<book>
 <title>Sample XML Thing</title>
 <author>
  <name>
   <first>Benjamin</first>
   <last>Smith</last>
  </name>
 </author>
 <chapter number="1">
  <title>Fisrt Chapter</title>
  <para>
   I think widgets are great.you should buy lots of them from
   <company>Springy widgets,Inc</company>
  </para>
 </chapter>
</book>

Process finished with exit code 0

4.dom类型参考

8.3使用xml-rpc
5.
代码：

#coding=utf-8
import xmlrpclib
url='http://liandesinian.blog.51cto.com/7737219/1565474'
s=xmlrpclib.ServerProxy(url)
catdata=s.meerkat.getCategories()
cattiles=[item['title'] for item in catdata]
cattiles.sort()
for item in cattiles:
    print item

运行结果：

D:\python\python.exe E:/code/python/unit8/un6.py

Process finished with exit code 0

6.
代码：

#coding=utf-8
import xmlrpclib,sys,textwrap

class NewsCat:
    def __init__(self,catdata):
        self.id=catdata['id']
        self.title=catdata['title']
    def __cmp__(self, other):
        return cmp(self.title,other.title)

class NewsSource:
    def __init__(self,url='http://www.oreillynet.com/meerkat/xml-rpc/server.php'):
        self.s=xmlrpclib.ServerProxy(url)
        self.loadcats()

    def loadcats(self):
        print "Loading categories...."
        catdata=self.s.meerkat.getCatgries()
        self.cats=[NewsCat(item) for item in catdata]
        self.cat.sort()

    def displaycats(self):
        numonline=0
        i=0
        for item in self.cats:
            sys.stdout.write("%2d:%20.20s"%(i+1,item.title))
            i+=1
            numonline+=1
            if numonline%3==0:
                sys.stdout.write("\n")
        if numonline!=0:
            sys.stdout.write("\n")

def promotcat(self):
    sys.__displaycats()
    sys.stdout.write("select a catgory or q to quit")
    selection = sys.stdin.readline().strip()
    if selection == 'q':
        sys.exit(0)
    return int(selection) - 1

def dispact(self, cat):
    items = self.s.meerkat.getItems({'category': cat,
                                     'ids': 1,
                                     'descriptions': 1,
                                     'categories': 1,
                                     'channels': 1,
                                     'data': 1,
                                     'num_items': 15})
    if not len(items):
        print "Sorry,no items in that category."
        sys.stdout.write("Press Enter to continue:")
        sys.stdin.readline()
        return
    while 1:
        print self.dispitemsummary(items)
        sys.stdout.write("select a catgory or q to quit")
        selection = sys.stdin.readline().strip()
        if selection=='q':
             return

        self.dispitem(items[int(selection)-1])

def dispitemsummary(self, items):
    counter = 0
    for item in items:
        print "%2d:%s"(counter + 1, item['title'])
        counter += 1

def dispitem(self, item):
    print "---%s---" % item['title']
    print "Posted on", item['data']
    print "Description:"
    print textwrap.fill(item['description'])
    print "\nlink:", item['link']
    sys.stdout.write("\nPress Enter to continue: ")
    sys.stdin.readline()
    n = NewsSource()
    while 1:
        cat = n.promotcat()
        n.dispact(cat)
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发表于 2017.03.18 12:03， 共 5305 人浏览

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