如何通过脚本标签使用python解析和beautifulsoup

Question

我试图提取帧标签，它是内部document.write功能的页面上，如下所示的属性：

<script language="javascript"> 
. 
. 
. 
document.write('<frame name="nav" src="/nav/index_nav.html" marginwidth="0" marginheight="0" scrolling="no" frameborder="0" border = "no" noresize>'); 
if (anchor != "") { 
    document.write('<frame name="body" src="http://content.members.fidelity.com/mfl/summary/0,,' + cusip + ',00.html?' + anchor + '" marginwidth="0" marginheight="0" scrolling="auto" frameborder="0" noresize>'); 
} else { 
    document.write('<frame name="body" src="http://content.members.fidelity.com/mfl/summary/0,,' + cusip + ',00.html" marginwidth="0" marginheight="0" scrolling="auto" frameborder="0" noresize>'); 
} 
document.write('</frameset>'); 


// end hiding --> 
</script> 

findAll('frame')方法没有帮助。有没有办法读取帧标签的内容？

我使用python 2.5和BeautifulSoup 3.0.8。

只要我能够得到结果，我也可以使用Python 3.1与BeautifulSoup 3.1 。

谢谢

Answer 1

你无法单独使用BeautifulSoup。 BeautifulSoup解析HTML到达浏览器（在任何重写或DOM操作之前），并且它不解析（更不用说执行）Javascript。

您可能想在这种特殊情况下使用简单的正则表达式。

Answer 2

Pyparsing可能会帮助您弥合JS和HTML的混合。此解析器查找包含带引号的字符串或多个带引号的字符串和标识符的字符串表达式的document.write语句，准评估字符串表达式，解析嵌入的<frame>标记，并将帧属性作为pyparsing ParseResults对象返回给您访问命名属性，就好像它们是对象属性或字典键（您的首选项）。

jssrc = """ 
<script language="javascript"> 
. 
. 
. 
document.write('<frame name="nav" src="/nav/index_nav.html" marginwidth="0" marginheight="0" scrolling="no" frameborder="0" border = "no" noresize>'); 
if (anchor != "") 
{ document.write('<frame name="body" src="http://content.members.fidelity.com/mfl/summary/0,,' + cusip + ',00.html?' + anchor + '" marginwidth="0" marginheight="0" scrolling="auto" frameborder="0" noresize>'); } 
else 
{ document.write('<frame name="body" src="http://content.members.fidelity.com/mfl/summary/0,,' + cusip + ',00.html" marginwidth="0" marginheight="0" scrolling="auto" frameborder="0" noresize>'); } 
document.write('</frameset>'); 
    // end hiding --> 
    </script>""" 

from pyparsing import * 

# define some basic punctuation, and quoted string 
LPAR,RPAR,PLUS = map(Suppress,"()+") 
qs = QuotedString("'") 

# use pyparsing helper to define an expression for opening <frame> 
# tags, which includes support for attributes also 
frameTag = makeHTMLTags("frame")[0] 

# some of our document.write statements contain not a sting literal, 
# but an expression of strings and vars added together; define 
# an identifier expression, and add a parse action that converts 
# a var name to a likely value 
ident = Word(alphas).setParseAction(lambda toks: evalvars[toks[0]]) 
evalvars = { 'cusip' : "CUSIP", 'anchor' : "ANCHOR" } 

# now define the string expression itself, as a quoted string, 
# optionally followed by identifiers and quoted strings added 
# together; identifiers will get translated to their defined values 
# as they are parsed; the first parse action on stringExpr concatenates 
# all the tokens; then the second parse action actually parses the 
# body of the string as a <frame> tag and returns the results of parsing 
# the tag and its attributes; if the parse fails (that is, if the 
# string contains something that is not a <frame> tag), the second 
# parse action will throw an exception, which will cause the stringExpr 
# expression to fail 
stringExpr = qs + ZeroOrMore(PLUS + (ident | qs)) 
stringExpr.setParseAction(lambda toks : ''.join(toks)) 
stringExpr.addParseAction(lambda toks: 
    frameTag.parseString(toks[0],parseAll=True)) 

# finally, define the overall document.write(...) expression 
docWrite = "document.write" + LPAR + stringExpr + RPAR 

# scan through the source looking for document.write commands containing 
# <frame> tags using scanString; print the original source fragment, 
# then access some of the attributes extracted from the <frame> tag 
# in the quoted string, using either object-attribute notation or 
# dict index notation 
for dw,locstart,locend in docWrite.scanString(jssrc): 
    print jssrc[locstart:locend] 
    print dw.name 
    print dw["src"] 
    print 

打印：

document.write('<frame name="nav" src="/nav/index_nav.html" marginwidth="0" marginheight="0" scrolling="no" frameborder="0" border = "no" noresize>') 
nav 
/nav/index_nav.html 

document.write('<frame name="body" src="http://content.members.fidelity.com/mfl/summary/0,,' + cusip + ',00.html?' + anchor + '" marginwidth="0" marginheight="0" scrolling="auto" frameborder="0" noresize>') 
body 
http://content.members.fidelity.com/mfl/summary/0,,CUSIP,00.html?ANCHOR 

document.write('<frame name="body" src="http://content.members.fidelity.com/mfl/summary/0,,' + cusip + ',00.html" marginwidth="0" marginheight="0" scrolling="auto" frameborder="0" noresize>') 
body 
http://content.members.fidelity.com/mfl/summary/0,,CUSIP,00.html