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Python .itertext()中的lxml错误;ValueError:输入对象没有元素:HtmlComment“;_Python_Lxml - Fatal编程技术网

Python .itertext()中的lxml错误;ValueError:输入对象没有元素:HtmlComment“;

Python .itertext()中的lxml错误;ValueError:输入对象没有元素:HtmlComment“;,python,lxml,Python,Lxml,我尝试使用elt.itertext()(v3.5.0b1)遍历子树的文本内容,如下所示: import lxml.html.soupparser as soupparser import requests doc = requests.get("http://f10.5post.com/forums/showthread.php?t=1142017").content tree = soupparser.fromstring(doc) nodes = tree.getchildren()

我尝试使用
elt.itertext()
(v3.5.0b1)遍历子树的文本内容,如下所示:

import lxml.html.soupparser as soupparser
import requests

doc = requests.get("http://f10.5post.com/forums/showthread.php?t=1142017").content
tree = soupparser.fromstring(doc)

nodes = tree.getchildren()

for elt in nodes:
    for t in elt.itertext():
         print t
但我一直在说一个错误

 File "src/lxml/iterparse.pxi", line 248, in lxml.etree.iterwalk.__init__ (src/lxml/lxml.etree.c:134032)
 File "src/lxml/apihelpers.pxi", line 67, in lxml.etree._rootNodeOrRaise (src/lxml/lxml.etree.c:15220)
ValueError: Input object has no element: HtmlComment
有没有办法跳过所有HTML注释?还有,这个错误实际上意味着什么

谢谢

这很正常

>>> from lxml import etree
>>> doc = '''
... <html><!-- PAGENAV POPUP -->
...     <div class="vbmenu_popup" id="pagenav_menu" style="display:none">
...             <table cellpadding="4" cellspacing="1" border="0">
...             <tr>
...                     <td class="thead" nowrap="nowrap">Go to Page...</td>
...             </tr>
...             <tr>
...                     <td class="vbmenu_option" title="nohilite">
...                     <form action="index.php" method="get" onsubmit="return this.gotopage()" id="pagenav_form">
...                             <input type="text" class="bginput" id="pagenav_itxt" style="font-size:11px" size="4" />
...                             <input type="button" class="button" id="pagenav_ibtn" value="Go" />
...                     </form>
...                     </td>
...             </tr>
...             </table>
...     </div>
... <!-- / PAGENAV POPUP -->
... </html>'''
>>> root = etree.fromstring(doc)
>>> nodes = root.getchildren()
>>> nodes
[<!-- PAGENAV POPUP -->, <Element div at 0x10367f290>, <!-- / PAGENAV POPUP -->]
>>> for elt in nodes:
...     for t in elt.itertext():
...         print t
... 
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "lxml.etree.pyx", line 1406, in lxml.etree._Element.itertext (src/lxml/lxml.etree.c:48845)
  File "lxml.etree.pyx", line 2763, in lxml.etree.ElementTextIterator.__cinit__ (src/lxml/lxml.etree.c:64747)
  File "iterparse.pxi", line 219, in lxml.etree.iterwalk.__init__ (src/lxml/lxml.etree.c:125303)
  File "apihelpers.pxi", line 72, in lxml.etree._rootNodeOrRaise (src/lxml/lxml.etree.c:13689)
ValueError: Input object has no element: lxml.etree._Comment
我得到了所有的文本和大量的空格。:)

如果仍要在节点列表上迭代。你可以凭直觉推断自然

>>> [item.tag for item in nodes]
[<built-in function Comment>, 'div', <built-in function Comment>]
>[节点中项目的item.tag]
[,'div',]
你也可以

>>> [item.__class__ for item in nodes]
[<type 'lxml.etree._Comment'>, <type 'lxml.etree._Element'>, <type 'lxml.etree._Comment'>]
>>>[节点中的项目.\uuuuuu类\uuuuuuuu]
[, ]

除非您使用PullParser@AndyG我想知道为什么lxml在这种特殊情况下会出错。希望我不需要跳过HTML注释来避免这个错误。我没有使用这个库,但我认为你可以轻松地完成你需要的
>>> for t in root.itertext():
...     print t
... 
>>> [item.tag for item in nodes]
[<built-in function Comment>, 'div', <built-in function Comment>]
>>> [item.__class__ for item in nodes]
[<type 'lxml.etree._Comment'>, <type 'lxml.etree._Element'>, <type 'lxml.etree._Comment'>]