问题描述
我试图使用Python的ElementTree解析，操纵和输出HTML： import sys
from cStringIO import StringIO
from xml.etree import ElementTree as ET
from htmlentitydefs import entitydefs
source = StringIO（< html>
< body>
< p>小于& lt< / p>
< p>不间断空间& nbsp;< / p>
< / body>
< / html>）
parser = ET.XMLParser（）
parser.parser.UseForeignDTD（True）
parser.entity.update（entitydefs ）
etree = ET.ElementTree（）
tree = etree.parse（source，parser = parser）
for p in tree.findall（'.// p'） ：
print ET.tostring（p，encoding ='UTF-8'）
我在Mac OS X 10.6上使用Python 2.7运行，我得到：
< p>小于< lt< ; / p为H.
追溯（最近的最后一次调用）：
文件bar.py，第20行，< module>
打印ET.tostring（p，encoding ='utf-8'）
文件/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/xml/etree/ElementTree。 py，第1120行，instring
ElementTree（element）.write（file，encoding，method = method）
文件/Library/Frameworks/Python.framework/Versions/2.7/lib/python2。 7 / xml / etree / ElementTree.py，第815行，写入
serialize（write，self._root，encoding，qnames，namespaces）
文件/Library/Frameworks/Python.framework/Versions /2.7/lib/python2.7/xml/etree/ElementTree.py，第931行，_serialize_xml
写（_escape_cdata（文本，编码））
文件/Library/Frameworks/Python.framework $ V $ s
UnicodeDecodeError：'ascii'编解码器无法解码位置19中的字节0xa0：序号不在范围（128）
我以为指定encoding ='UTF-8'w应该照顾不间断的空间人物，但显然没有。我应该怎么办？
0xA0是一个latin1字符，而不是一个unicode字符，p.text的值在循环是一个str而不是unicode，这意味着为了在utf-8中进行编码，它必须首先被Python隐式转换为unicode字符串（即使用decode）。当它这样做它假定ascii，因为它没有被告知任何其他。 0xa0不是有效的ASCII字符，但它是一个有效的latin1字符。
您的latin1字符而不是Unicode字符的原因是因为entitydefs是一个映射到latin1编码字符串。您需要可以从htmlentitydef.name2codepoint获取的unicode代码点
下面的版本应该为您解决：
来自cStringIO的import $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
$ b source = StringIO（< html>
< body>
< p>小于& lt< / p>
< p>
parser = ET.XMLParser（）
< / p>
< / body>
parser.parser.UseForeignDTD（True）
parser.entity.update（（x，unichr（i））for x，i in name2codepoint.iteritems（））
etree = ET.ElementTree（）
tree = etree.parse（source，parser = parser）
for p in tree.findall（'.// p'）：
print ET.tostring（p，encoding = 'UTF-8'）
I'm trying to parse, manipulate, and output HTML using Python's ElementTree:
import sys
from cStringIO import StringIO
from xml.etree import ElementTree as ET
from htmlentitydefs import entitydefs
source = StringIO("""<html>
<body>
<p>Less than <</p>
<p>Non-breaking space </p>
</body>
</html>""")
parser = ET.XMLParser()
parser.parser.UseForeignDTD(True)
parser.entity.update(entitydefs)
etree = ET.ElementTree()
tree = etree.parse(source, parser=parser)
for p in tree.findall('.//p'):
print ET.tostring(p, encoding='UTF-8')
When I run this using Python 2.7 on Mac OS X 10.6, I get:
<p>Less than <</p>
Traceback (most recent call last):
File "bar.py", line 20, in <module>
print ET.tostring(p, encoding='utf-8')
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/xml/etree/ElementTree.py", line 1120, in tostring
ElementTree(element).write(file, encoding, method=method)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/xml/etree/ElementTree.py", line 815, in write
serialize(write, self._root, encoding, qnames, namespaces)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/xml/etree/ElementTree.py", line 931, in _serialize_xml
write(_escape_cdata(text, encoding))
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/xml/etree/ElementTree.py", line 1067, in _escape_cdata
return text.encode(encoding, "xmlcharrefreplace")
UnicodeDecodeError: 'ascii' codec can't decode byte 0xa0 in position 19: ordinal not in range(128)
I thought that specifying "encoding='UTF-8'" would take care of the non-breaking space character, but apparently it doesn't. What should I do instead?
0xA0 is a latin1 character, not a unicode character and the value of p.text in the loop is a str and not unicode, that means that in order to encode it in utf-8 it must first be converted by Python implicitly into a unicode string (i.e. using decode). When it is doing this it assumes ascii since it wasn't told anything else. 0xa0 is not a valid ascii character, but it is a valid latin1 character.
The reason you have latin1 characters instead of unicode characters is because entitydefs is a mapping of names to latin1 encode strings. You need the unicode code point which you can get from htmlentitydef.name2codepoint
The version below should fix it for you:
import sys
from cStringIO import StringIO
from xml.etree import ElementTree as ET
from htmlentitydefs import name2codepoint
source = StringIO("""<html>
<body>
<p>Less than <</p>
<p>Non-breaking space </p>
</body>
</html>""")
parser = ET.XMLParser()
parser.parser.UseForeignDTD(True)
parser.entity.update((x, unichr(i)) for x, i in name2codepoint.iteritems())
etree = ET.ElementTree()
tree = etree.parse(source, parser=parser)
for p in tree.findall('.//p'):
print ET.tostring(p, encoding='UTF-8')
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