Import HTMLParser from html.parser for Python 3.x

IPython/nbconvert/filters/citation.py

@@ -1,107 +1,111 b''
 """Citation handling for LaTeX output."""
 
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
+from IPython.utils.py3compat import PY3
+if PY3:
+    from html.parser import HTMLParser
+else:
 from HTMLParser import HTMLParser
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 __all__ = ['citation2latex']
 
 
 def citation2latex(s):
     """Parse citations in Markdown cells.
     
     This looks for HTML tags having a data attribute names `data-cite`
     and replaces it by the call to LaTeX cite command. The tranformation
     looks like this:
     
     `<cite data-cite="granger">(Granger, 2013)</cite>`
     
     Becomes
     
     `\\cite{granger}`
     
     Any HTML tag can be used, which allows the citations to be formatted
     in HTML in any manner.
     """
     parser = CitationParser()
     parser.feed(s)
     parser.close()
     outtext = u''
     startpos = 0
     for citation in parser.citelist:
             outtext += s[startpos:citation[1]]
             outtext += '\\cite{%s}'%citation[0]
             startpos = citation[2] if len(citation)==3 else -1
     outtext += s[startpos:] if startpos != -1 else ''
     return outtext
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class CitationParser(HTMLParser):
     """Citation Parser
 
     Replaces html tags with data-cite attribute with respective latex \\cite.
     
     Inherites from HTMLParser, overrides:
      - handle_starttag
      - handle_endtag
     """
     # number of open tags
     opentags = None
     # list of found citations
     citelist = None
     # active citation tag
     citetag = None
 
     def __init__(self):
         self.citelist = []
         self.opentags = 0
         HTMLParser.__init__(self)
     
     def get_offset(self):
         # Compute startposition in source
         lin, offset = self.getpos()
         pos = 0
         for i in range(lin-1):
             pos = self.data.find('\n',pos) + 1
         return pos + offset
         
     def handle_starttag(self, tag, attrs):
         # for each tag check if attributes are present and if no citation is active
         if self.opentags == 0 and len(attrs)>0:
             for atr, data in attrs:
                 if atr.lower() == 'data-cite':
                     self.citetag = tag
                     self.opentags = 1
                     self.citelist.append([data, self.get_offset()])
                     return
                 
         if tag == self.citetag:
             # found an open citation tag but not the starting one  
             self.opentags += 1
   
     def handle_endtag(self, tag):
         if tag == self.citetag:
             # found citation tag check if starting one
             if self.opentags == 1:
                 pos = self.get_offset()
                 self.citelist[-1].append(pos+len(tag)+3)
             self.opentags -= 1
         
     def feed(self, data):
         self.data = data
         HTMLParser.feed(self, data)