1.善于利用soup節點的parent屬性
比如對于已經得到了如下html代碼:
<td style="padding-left:0" width="60%"><label>November</label><input type="Hidden" id="cboMonth1" name="cboMonth1" value="11"></td><td style="padding-right:0;" width="40%"> <label>2012</label> <input type="Hidden" id="cboYear1" name="cboYear1" value="2012"></td>
的soup變量eachMonthHeader了。
想要提取其中的
Month的label的值:November
和Year的label的值:2012
最簡單,也是最省事的辦法是,直接搜兩個label,然后肯定會找到這兩個label,然后分別對應著Month和Year的label,然后獲得對應的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
但是很明顯,這樣的邏輯性很不好,而且萬一處理多個這樣的soup變量,而且兩者的順便顛倒了,那么結果也就錯誤了。
此時,可以考慮利用soup變量的parent屬性,從一個soup變量本身,獲得其上一級的soup變量。
示例代碼如下:
# <td style="padding-left:0" width="60%"><label>November</label># <input type="Hidden" id="cboMonth1" name="cboMonth1" value="11"># </td><td style="padding-right:0;" width="40%"> # <label>2012</label> # <input type="Hidden" id="cboYear1" name="cboYear1" value="2012"># </td>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;
我們再來看一個例子:
from BeautifulSoup import BeautifulSoup doc = ['<html><head><title>Page title</title></head>', '<body><p id="firstpara" align="center">This is paragraph <b>one</b>.', '<p id="secondpara" align="blah">This is paragraph <b>two</b>.', '</html>']soup = BeautifulSoup(''.join(doc))print soup.prettify()# <html># <head># <title># Page title# </title># </head># <body># <p id="firstpara" align="center"># This is paragraph# <b># one# </b># .# </p># <p id="secondpara" align="blah"># This is paragraph# <b># two# </b># .# </p># </body># </html>
這個例子中,<HEAD> Tag的parent是<HTML> Tag. <HTML> Tag 的parent是BeautifulSoup 剖析對象自己。 剖析對象的parent是None. 利用parent,你可以向前遍歷剖析樹。
soup.head.parent.name# u'html'soup.head.parent.parent.__class__.__name__# 'BeautifulSoup'soup.parent == None# True
2.當解析非UTF-8或ASCII編碼類型的HTML時,需要指定對應的字符編碼
當html為ASCII或UTF-8編碼時,可以不指定html字符編碼,便可正確解析html為對應的soup:
#這里respHtml是ASCII或UTF-8編碼,此時可以不指定編碼類型,即可正確解析出對應的soupsoup = BeautifulSoup(respHtml);
當html為其他類型編碼,比如GB2312的話,則需要指定相應的字符編碼,BeautifulSoup才能正確解析出對應的soup:
比如:
#此處respHtml是GB2312編碼的,所以要指定該編碼類型,BeautifulSoup才能解析出對應的souphtmlCharset = "GB2312";soup = BeautifulSoup(respHtml, fromEncoding=htmlCharset);