Parsing UTF-8/unicode strings with lxml HTML

python parsing unicode utf-8 lxml
karlcow picture karlcow · Aug 13, 2012 · Viewed 13k times · Source

I have been trying to parse with etree.HTML() a text encoded as UTF-8 without success.

→ python
Python 2.7.1 (r271:86832, Jun 16 2011, 16:59:05) 
[GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2335.15.00)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from lxml import etree
>>> import requests
>>> headers = {'User-Agent': "Opera/9.80 (Macintosh; Intel Mac OS X 10.8.0) Presto/2.12.363 Version/12.50"}
>>> r = requests.get("http://www.rakuten.co.jp/", headers=headers)
>>> r.status_code
200
>>> r.headers
{'x-cache': 'MISS from www.rakuten.co.jp', 'transfer-encoding': 'chunked', 'set-cookie': 'wPzd=lng%3DNA%3Acnt%3DCA; expires=Tue, 13-Aug-2013 16:51:38 GMT; path=/; domain=www.rakuten.co.jp', 'server': 'Apache', 'pragma': 'no-cache', 'cache-control': 'private', 'date': 'Mon, 13 Aug 2012 16:51:38 GMT', 'content-type': 'text/html; charset=EUC-JP'}
>>> responsetext = r.text

So far so good. The response text is good and it is a unicode string. Now if I'm trying to get the list of CSS URIs. No issue either.

>>> tree = etree.HTML(responsetext)
>>> csspathlist = tree.xpath('//link[@rel="stylesheet"]/@href')
>>> csspathlist
['http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/opt/css/normal/common.css?v=1207111500', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/opt/css/normal/layout.css?v=1207111500', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/opt/css/normal/sidecolumn.css?v=1207111500', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/beta/css/liquid/api.css?v=1207111500', '/com/inc/home/20080930/beta/css/liquid/myrakuten_dpgs.css', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/opt/css/normal/leftcolumn.css?v=1207111500', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/opt/css/normal/header.css?v=1207111500', '/com/inc/home/20080930/opt/css/normal/footer.css', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/beta/css/liquid/ipad.css', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/opt/css/normal/genre.css?v=1207111500', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/opt/css/normal/supersale.css?v=1207111500', '/com/inc/home/20080930/beta/css/liquid/rakuten_membership.css', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/beta/css/noscript/set.css?v=1207111500', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/beta/css/liquid/suggest-2.0.1.css?v=1204231500', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/beta/css/liquid/liquid_banner.css?v=1203011138', 'http://a.ichiba.jp.rakuten-static.com/com/inc/home/20080930/beta/css/liquid/area_announce.css?v=1203011138']

Now let's change from unicode to UTF-8 and request again the list of CSS URIs.

>>> htmltext = responsetext.encode('utf-8')
>>> tree2 = etree.HTML(htmltext)
>>> csspathlist2 = tree2.xpath('//link[@rel="stylesheet"]/@href')
>>> csspathlist2
[]

I get an empty list.

>>> etree.tostring(tree2)
'<html lang="ja" xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://ogp.me/ns#" xmlns:fb="http://www.facebook.com/2008/fbml"><head><meta http-equiv="Content-Type" content="text/html; charset=EUC-JP"/><meta http-equiv="Content-Style-Type" content="text/css"/><meta http-equiv="Content-Script-Type" content="text/javascript"/><title/></head></html>'

Indeed, the second parsing stopped right away after the first Japanese character in the title.

<meta http-equiv="Content-Script-Type" content="text/javascript"/>
<title> 【楽天市場】Shopping is Entertainment! ： インターネット最大級の通信販売、通販オンラインショッピングコミュニティ </title>

I'm still trying to understand what I have done wrong.

Answer

karlcow picture karlcow · Aug 13, 2012

Ok and just found. Writing the question on StackOverflow helps often.

etree.HTML() is trying to guess the encoding according to the meta in the document

<meta http-equiv="Content-Type" content="text/html; charset=EUC-JP"/>

In this case, I have converted manually the document to utf-8, which means it is not anymore the Japanese encoding: EUC-JP. So to solve the issue is just a matter of forcing the HTML parser to understand utf-8. In our case the code becomes:

>>> myparser = etree.HTMLParser(encoding="utf-8")
>>> tree = etree.HTML(htmltext, parser=myparser)

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