I'm trying to build an xml document from scratch using xml.dom.minidom. Everything was going well until I tried to make a text node with a ® (Registered Trademark) symbol in. My objective is for when I finally hit print mydoc.toxml() this particular node will actually contain a ® symbol.
First I tried:
import xml.dom.minidom as mdom
data = '®'
which gives the rather obvious error of:
File "C:\src\python\HTMLGen\test2.py", line 3
SyntaxError: Non-ASCII character '\xae' in file C:\src\python\HTMLGen\test2.py on line 3, but no encoding declared; see http://www.python.or
g/peps/pep-0263.html for details
I have of course also tried changing the encoding of my python script to 'utf-8' using the opening line comment method, but this didn't help.
So I thought
import xml.dom.minidom as mdom
data = '®' #Both accepted xml encodings for registered trademark
data = '®'
text = mdom.Text()
text.data = data
print data
print text.toxml()
But because when I print text.toxml(), the ampersands are being escaped, I get this output:
®
®
My question is, does anybody know of a way that I can force the ampersands not to be escaped in the output, so that I can have my special character reference carry through to the XML document?
Basically, for this node, I want print text.toxml() to produce output of ® or ® in a happy and cooperative way!
EDIT 1:
By the way, if minidom actually doesn't have this capacity, I am perfectly happy using another module that you can recommend which does.
EDIT 2:
As Hugh suggested, I tried using data = u'®' (while also using data # -*- coding: utf-8 -*- Python source tags). This almost helped in the sense that it actually caused the ® symbol itself to be outputted to my xml. This is actually not the result I am looking for. As you may have guessed by now (and perhaps I should have specified earlier) this xml document happens to be an HTML page, which needs to work in a browser. So having ® in the document ends up causing rubbish in the browser (® to be precise!).
I also tried:
data = unichr(174)
text.data = data.encode('ascii','xmlcharrefreplace')
print text.toxml()
But of course this lead to the same origional problem where all that happens is the ampersand gets escaped by .toxml().
My ideal scenario would be some way of escaping the ampersand so that the XML printing function won't "escape" it on my behalf for the document (in other words, achieving my original goal of having ® or ® appear in the document).
Seems like soon I'm going to have to resort to regular expressions!
EDIT 2a:
Or perhaps not. Seems like getting my html meta information correct <META http-equiv="Content-Type" Content="text/html; charset=UTF-8"> could help, but I'm not sure yet how this fits in with the xml structure...
Two options that work, one with the escaping ® and the other without. It's not really obvious why you want escaping ... it's 6 bytes instead of the 2 or 3 bytes for non-CJK characters.
import xml.dom.minidom as mdom
text = mdom.Text()
# Start with unicode
text.data = u'\xae'
f = open('reg1.html', 'w')
f.write("header saying the file is ascii")
uxml = text.toxml()
bxml = uxml.encode('ascii', 'xmlcharrefreplace')
f.write(bxml)
f.close()
f = open('reg2.html', 'w')
f.write("header saying the file is UTF-8")
xml = text.toxml(encoding='UTF-8')
f.write(xml)
f.close()
If I understand correctly, what you really want is to be able to create a text node from a unicode object (e.g. u'®' or u'\u00ae') and then have toxml() output unicode characters encoded as entities (e.g. ®). Looking at the source of minidom.py, however, it seems that minidom doesn't support entity encoding on output except the special cases of &, ", < and >.
You also ask about alternative modules that could help, however. There are several possible candidates, but ElementTree (xml.etree) seems to do the appropriate encoding. For example, if you take the first example from this blog post by Doug Hellmann but replace:
child_with_tail.text = 'This child has regular text.'
... with:
child_with_tail.text = u'This child has regular text \u00ae.'
... and run the script, you should see the output contains:
This child has regular text®.
You could also use the lxml implementation of ElementTree in that example just by replacing the import statement with:
from lxml.etree import Element, SubElement, Comment, tostring
Update: the alternative answer from John Machin takes the nice approach of running .encode('ascii', 'xmlcharrefreplace') on the output from minidom's toxml(), which converts any non-ASCII characters to their equivalent XML numeric character references.
Default unescape:
from xml.sax.saxutils import unescape
unescape("< & >")
The result is,
'< & >'
And, unescape more:
unescape("' "", {"'": "'", """: '"'})
Check details here, https://wiki.python.org/moin/EscapingXml
Related
I am trying to extract some information from an input xml file and print it into an output file by using lxml and xpath instructions.
I am getting a problem when reading an xml tag like the following
...
<editor> Barnes & Nobel </editor>
...
In order to parse the xml file and print the editor content I use (there is always only one editor in the xml):
parser = etree.XMLParser(encoding='utf-8')
docTree = etree.parse( io.BytesIO(open(inputXML, "r").read()), parser )
print docTree.xpath('//editor')[0].text
My problem is that the & gets converted at some point into '&', which messes up my further processing.
How can I ensure that the & symbol will not be "decoded"?
I know this will sound presumptuous, but you want the data to be "&". That is the text content of the XML element. If you have later processing that needs it as "&", then you need a step that will XML- (or HTML-) encode it back to "&",
You cannot ask an XML parser to parse your document and not turn "&" into "&". It won't do it.
I finally found the answer to my own question in the answer of How do I escape ampersands in XML so they are rendered as entities in HTML?
In my code I have added an intermediate step to ensure that all & characters will remain the same at the output. This is
parser = etree.XMLParser(encoding='utf-8')
xmlText = open(inputXML, "r").read().replace("&", "&")
docTree = etree.parse( io.BytesIO(xmlText), parser )
print docTree.xpath('//editor')[0].text
In fact, just in case, I have applied the same recipe to other possible entities in XML as defined in http://en.wikipedia.org/wiki/List_of_XML_and_HTML_character_entity_references#Predefined%5Fentities%5Fin%5FXML
Okay, I feel a bit lost right now. I have some problems with unicode (or utf-8 ?)
I am using Python3.3 on linux (But I have the same problem on windows).
I try to create an XML file with Elementtree.
item = ET.Element("item")
item_title = Et.SubElement(item, "title")
That is of course not everything, just an example.
So now I want to have the tag 'title' have a text like this (replace the ##Content## with random content, doesnt matter so much):
# Thats how I create the text for the tag
item.title.text = u'<![CDATA[##CONTENT##]>'
# This is how I want it to look like
<title><![CDATA[##CONTENT##]></title>
# Thats what I get
<title><![CDATA[##CONTENT##]></title>
# These are some of the things I tried for writing it to an xml file
ET.ElementTree(item).write(myOutputFile, encoding="unicode")
myOutputFile.write(ET.tostring(item, encoding='unicode', method='xml')))
myOutputFile.write(str(ET.tostring(item, encoding='utf-8', method='xml')))
myOutputFile.write(str(ET.tostring(item)
# Oh and thats how I open the file for writing
myOutputFile = codecs.open(HereIsMyFile, 'w', encoding='utf-8')
I tried to search and found some similar sounding problems (some of the things I tried are from SO already), but none seems to work. They changed some stuff in the output, but never showed the < or >.
I also noticed, if I use utf-8 I have to use str() when writing to the file. That got me also confused about the difference in unicode and utf-8, I tried to read some stuff about that but that didn't really help me in my actual problem.
At this point I don't really know where to look for my error and I would love a hint where to look.
Is it the way I write to the file? How I open it?
Or is it Elementtree causing the error? (I didn't try something else, like lxml, because well, that would mean rewriting a lot of stuff I guess).
I hope you can help me and if something isn't clear I will try to explain it a bit better!
Edit: Oh and I also tried to open the file without codecs, because I somewhere read it is not needed anymore in Python3.x but I wasn't so sure anymore, so I tried it.
The correct way to write an XML document with ElementTree is:
with codecs.open(HereIsMyFile, 'w', encoding='utf-8'):
root.write(myOutputFile)
If you specify an encoding for write(), you must use what the XML standard defines. unicode isn't an encoding, it's a standard.
ElementTree doesn't support CDATA. The effect you're seeing is that ElementTree notices special characters in the text of the node and it escapes them; there is no way to prevent that.
This answer contains the implementation of a CDATA element: How to output CDATA using ElementTree
There seem to be a couple of layers of confusion here.
Taking the lower level first: encodings such as UTF-8 convert Unicode characters into bytes. Your problem is that the characters in your generated XML aren’t the ones you want, not with how those characters are stored as bytes, so there isn’t anything to fix there.
Secondly, you seem to be expecting the wrong thing from this line:
item.title.text = u'<![CDATA[##CONTENT##]>'
This tells ElementTree that you want that text in the parsed document. Consider this:
item.title.text = u'I <3 ASCII art.'
ElementTree won’t store that directly in the markup: it’ll turn it into
<title>I <3 ASCII art.</title>
Likewise:
item.title.text = u"This </title> isn’t the end of the title"
becomes
<title>This </title> isn’t the end of the title</title>
Hopefully you can see the value of this: no matter what text you put in there, it won’t break the element markup, or indeed affect it in any way.
Note that because of this automatic conversion, you very likely don’t need CDATA sections at all.
If for some reason you do, though, you can do it by stating it explicitly (using lxml.etree):
title = lxml.etree.Element('title')
title.text = lxml.etree.CDATA('###CONTENT###')
print(lxml.etree.tostring(title))
outputs:
<title><![CDATA[###CONTENT###]]></title>
Update:
My code works fine on most Hebrew page, but fails on 10% of them. I was unfortunate enough to start with two 'bad' ones.
Here's an example of a 'good' page: http://m.sport5.co.il/Pages/Article.aspx?articleId=154765,
and this is a 'bad' one: http://www.havoda.org.il/Web/Default.aspx.
I still need to deal with the bad ones, and I still don't know how...
Original question:
I'm using lxml.html to parse HTML, and extract only text (to be later used for text classification). I couldn't manage to properly deal with unicode (Hebrew text, in my case).
The tree elements don't seem to be encoded correctly:
When I look at element[i].text , where type(element[i].text) = UnicodeType, I see something like this: "u'\xd7\x9e\xd7\xa9\xd7\x94 \xd7\xa9\xd7\xa8\xd7\xaa (1955-1954)'", and this is not right - this entity cannot be encoded or decoded! (or I haven't found how...) Printing it brings, of course, something like this: "××©× ×©×¨×ª (1955-1954)", and that's not Hebrew...
A workable text string should look like:
1. u'\u05de\u05e9\u05d4 \u05e9\u05e8\u05ea (1955-1954)' - a proper unicode string; or:
2. '\xd7\x9e\xd7\xa9\xd7\x94 \xd7\xa9\xd7\xa8\xd7\xaa (1955-1954)' - unicode encoded into a regular text string; but not:
3. u'\xd7\x9e\xd7\xa9\xd7\x94 \xd7\xa9\xd7\xa8\xd7\xaa (1955-1954)' - a useless hybrid entity ('ascii' codec can't decode byte...)
What do I do to solve it? What am I doing wrong? Here's the code I'm using:
import lxml.html as lh
from types import *
f = urlopen(url)
html = f.read()
root = lh.fromstring(html)
all_elements = root.cssselect('*')
all_text = ''
for i in range(len(all_elements)):
if all_elements[i].tag not in ['script','style']:
if type(all_elements[i].text) in [StringType, UnicodeType]:
all_text = all_text + all_elements[i].text.strip() + ' '
Everything works just fine with pure English (non unicode) html.
Almost all of the answers here refer to lxml.etree, and not lxml.html that I'm using. Do I have to switch? (I don't want to...)
probably (but hard to know for sure without having the data), the page is UTF-8 encoded, but the HTML parser defaults to iso-8859-1 (as opposed to the XML parser which defaults to UTF-8)
I'm using minidom to parse an xml file and it threw an error indicating that the data is not well formed. I figured out that some of the pages have characters like ไà¸à¹€à¸Ÿà¸¥ &, causing the parser to hiccup. Is there an easy way to clean the file before I start parsing it? Right now I'm using a regular expressing to throw away anything that isn't an alpha numeric character and the </> characters, but it isn't quite working.
Try
xmltext = re.sub(u"[^\x20-\x7f]+",u"",xmltext)
It will get rid of everything except 0x20-0x7F range.
You may start from \x01, if you want want to keep control characters like tab, line breaks.
xmltext = re.sub(u"[^\x01-\x7f]+",u"",xmltext)
Take a look at µTidyLib, a Python wrapper to TidyLib.
If you do need the data with the strange characters you could, in stead of just stripping them, convert them to codes the XML parser can understand.
You could have a look at the unicodedata package, especially the normalize method.
I haven't used it myself, so I can't tell you all that much, but you could ask again here on SO if you decide you're going to convert and keep that data.
>>> import unicodedata
>>> unicodedata.normalize("NFKD" , u"ไภเฟล &")
u'a\u03001\u201ea\u0300 \u0327 a\u03001\u20aca\u0300 \u0327Y\u0308a\u0300 \u0327\xa5 &'
It looks like you're dealing with data which are saved with some kind of encoding "as if" they were ASCII. XML file should normally be UTF8, and SAX (the underlying parser used by minidom) should handle that, so it looks like something's wrong in that part of the processing chain. Instead of focusing on "cleaning up" I'd first try to make sure the encoding is correct and correctly recognized. Maybe a broken XML directive? Can you edit your Q to show the first few lines of the file, especially the <?xml ... directive at the very start?
I'd throw out all non-ASCII characters which can be identified by having the 8th bit (0x80) set (128 .. 255 respectively 0x80 .. 0xff).
You could read in the file into a Python string named old_str
Then perform a filter call in conjunction with a lambda statement:
new_str = filter(lambda x: x in string.ascii_letters, old_str)
Parse new_str
Many ways exist to accomplish stripping non-ASCII characters from a string.
This question might be related: How to check if a string in Python is in ASCII?
I need to have following attribute value in my XML node:
CommandLine="copy $(TargetPath) ..\..\
echo dummy > dummy.txt"
Actually this is part of a .vcproj file generated in VS2008.

 means line break, as there should be 2 separate commands.
I'm using Python 2.5 with minidom to parse XML - but unfortunately I don't know how to store sequences like
, the best thing i can get is &#x0D;.
How can I store exactly
?
UPD : Exactly speaking i have to store not &, but \r\n sequence in form of


I'm using Python 2.5 with minidom to parse XML - but unfortunately I don't know how to store sequences like
Well, you can't specify that you want hex escapes specifically, but according to the DOM LS standard, implementations should change \r\n in attribute values to character references automatically.
Unfortunately, minidom doesn't:
>>> from xml.dom import minidom
>>> document= minidom.parseString('<a/>')
>>> document.documentElement.setAttribute('a', 'a\r\nb')
>>> document.toxml()
u'<?xml version="1.0" ?><a a="a\r\nb"/>'
This is a bug in minidom. Try the same in another DOM (eg. pxdom):
>>> import pxdom
>>> document= pxdom.parseString('<a/>')
>>> document.documentElement.setAttribute('a', 'a\r\nb')
>>> document.pxdomContent
u'<?xml version="1.0" ?><a a="a
b"/>'
You should try storing the actual characters (ASCII 13 and ASCII 10) in the attribute value, instead of their already-escaped counterparts.
EDIT: It looks like minidom does not handle newlines in attribute values correctly.
Even though a literal line break in an attribute value is allowed, but it will face normalization upon document parsing, at which point it is converted to a space.
I filed a bug in this regard: http://bugs.python.org/issue5752
An ampersand is a special character in XML and as such most xml parsers require valid xml in order to function. Let minidom escape the ampersand for you (really it should already be escaped) and then when you need to display the escaped value, unescape it.