Question

我试图在页面上提取document.write函数内的帧标记的属性，如下所示：

<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？

我正在使用python 2.5和BeautifulSoup 3.0.8。

我也愿意使用带有BeautifulSoup 3.1的python 3.1 只要我能得到结果。

由于

Answer 1

单独使用BeautifulSoup无法做到这一点。 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。

在这种特殊情况下，您可能希望使用简单的正则表达式。

Answer 2

Pyparsing可以帮助您弥补JS和HTML的混合。此解析器查找包含带引号的字符串的document.write语句或带有几个带引号的字符串和标识符的字符串表达式，对字符串表达式进行准评估，为嵌入的<frame>标记解析它，并将帧属性返回为一个pyparsing ParseResults对象，它允许您访问命名属性，就好像它们是对象属性或dict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

如何使用python和beautifulsoup解析脚本标记

2 个答案: