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Python使用Beautiful Soup注意事项
1.善于利用soup节点的parent属性比如对于已经得到了如下html代码：November 2012 的soup变量eachMonthHeader了。想要提取其中的Month的label的值：November和Year的label的值：2012最简单，也是最省事的办法是，直接搜两个label，然后肯定会找到这两个label，然后分别对应着Month和Year的label，然后获得对应的string即可：foundTwoLabel = eachMonthHeader.findAll("label");print "foundTwoLabel=",foundTwoLabel;monthLabel = foundTwoLabel[0];yearLabel = foundTwoLabel[1]; monthStr = monthLabel.string;yearStr = yearLabel.string; print "monthStr=",monthStr; # monthStr= Novemberprint "yearStr=",yearStr; # yearStr= 2012但是很明显，这样的逻辑性很不好，而且万一处理多个这样的soup变量，而且两者的顺便颠倒了，那么结果也就错误了。此时，可以考虑利用soup变量的parent属性，从一个soup变量本身，获得其上一级的soup变量。示例代码如下：# November# # # 2012 # # foundCboMonth = eachMonthHeader.find("input", {"id":re.compile("cboMonth\d+")});#print "foundCboMonth=",foundCboMonth;tdMonth = foundCboMonth.parent;#print "tdMonth=",tdMonth;tdMonthLabel = tdMonth.label;#print "tdMonthLabel=",tdMonthLabel;monthStr = tdMonthLabel.string;print "monthStr=",monthStr; foundCboYear = eachMonthHeader.find("input", {"id":re.compile("cboYear\d+")});#print "foundCboYear=",foundCboYear;tdYear = foundCboYear.parent;#print "tdYear=",tdYear;tdYearLabel = tdYear.label;#print "tdYearLabel=",tdYearLabel;yearStr = tdYearLabel.string;print "yearStr=",yearStr;我们再来看一个例子：from BeautifulSoup import BeautifulSoup doc = ['', '

This is paragraph one.', '

This is paragraph two.', '']soup = BeautifulSoup(''.join(doc))print soup.prettify()# # # # # #

# This is paragraph# # one# # .#

#

# This is paragraph# # two# # .#

# # 这个例子中， Tag的parent是 Tag. Tag 的parent是BeautifulSoup 剖析对象自己。 剖析对象的parent是None. 利用parent，你可以向前遍历剖析树。soup.head.parent.name# u'html'soup.head.parent.parent.__class__.__name__# 'BeautifulSoup'soup.parent == None# True2.当解析非UTF-8或ASCII编码类型的HTML时，需要指定对应的字符编码当html为ASCII或UTF-8编码时，可以不指定html字符编码，便可正确解析html为对应的soup：#这里respHtml是ASCII或UTF-8编码，此时可以不指定编码类型，即可正确解析出对应的soupsoup = BeautifulSoup(respHtml);当html为其他类型编码，比如GB2312的话，则需要指定相应的字符编码，BeautifulSoup才能正确解析出对应的soup：比如：#此处respHtml是GB2312编码的，所以要指定该编码类型，BeautifulSoup才能解析出对应的souphtmlCharset = "GB2312";soup = BeautifulSoup(respHtml, fromEncoding=htmlCharset);