Backport PR #4092: nbconvert: Fix for unicode html headers, Windows + Python 2.x

Closes  #3818

IPython/nbconvert/filters/strings.py

@@ -1,183 +1,183 b''
 # coding: utf-8
 """String filters.
 
 Contains a collection of useful string manipulation filters for use in Jinja
 templates.
 """
 #-----------------------------------------------------------------------------
 # 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
 #-----------------------------------------------------------------------------
 
 import os
 import re
 import textwrap
 from xml.etree import ElementTree
 
 from IPython.core.interactiveshell import InteractiveShell
 from IPython.utils import py3compat
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 __all__ = [
     'wrap_text',
     'html2text',
     'add_anchor',
     'strip_dollars',
     'strip_files_prefix',
     'comment_lines',
     'get_lines',
     'ipython2python',
     'posix_path',
 ]
 
 
 def wrap_text(text, width=100):
     """ 
     Intelligently wrap text.
     Wrap text without breaking words if possible.
     
     Parameters
     ----------
     text : str
         Text to wrap.
     width : int, optional
         Number of characters to wrap to, default 100.
     """
 
     split_text = text.split('\n')
     wrp = map(lambda x:textwrap.wrap(x,width), split_text)
     wrpd = map('\n'.join, wrp)
     return '\n'.join(wrpd)
 
 
 def html2text(element):
     """extract inner text from html
     
     Analog of jQuery's $(element).text()
     """
     if isinstance(element, py3compat.string_types):
         element = ElementTree.fromstring(element)
     
     text = element.text or ""
     for child in element:
         text += html2text(child)
     text += (element.tail or "")
     return text
 
 
 def add_anchor(html):
     """Add an anchor-link to an html header tag
     
     For use in heading cells
     """
-    h = ElementTree.fromstring(py3compat.cast_bytes_py2(html))
+    h = ElementTree.fromstring(py3compat.cast_bytes_py2(html, encoding='utf-8'))
     link = html2text(h).replace(' ', '-')
     h.set('id', link)
     a = ElementTree.Element("a", {"class" : "anchor-link", "href" : "#" + link})
     a.text = u'¶'
     h.append(a)
 
     # Known issue of Python3.x, ElementTree.tostring() returns a byte string
     # instead of a text string.  See issue http://bugs.python.org/issue10942
     # Workaround is to make sure the bytes are casted to a string.
     return py3compat.decode(ElementTree.tostring(h), 'utf-8')
 
 
 def strip_dollars(text):
     """
     Remove all dollar symbols from text
     
     Parameters
     ----------
     text : str
         Text to remove dollars from
     """
 
     return text.strip('$')
 
 
 files_url_pattern = re.compile(r'(src|href)\=([\'"]?)files/')
 
 def strip_files_prefix(text):
     """
     Fix all fake URLs that start with `files/`,
     stripping out the `files/` prefix.
     
     Parameters
     ----------
     text : str
         Text in which to replace 'src="files/real...' with 'src="real...'
     """
     return files_url_pattern.sub(r"\1=\2", text)
 
 
 def comment_lines(text, prefix='# '):
     """
     Build a Python comment line from input text.
     
     Parameters
     ----------
     text : str
         Text to comment out.
     prefix : str
         Character to append to the start of each line.
     """
     
     #Replace line breaks with line breaks and comment symbols.
     #Also add a comment symbol at the beginning to comment out
     #the first line.
     return prefix + ('\n'+prefix).join(text.split('\n')) 
 
 
 def get_lines(text, start=None,end=None):
     """
     Split the input text into separate lines and then return the 
     lines that the caller is interested in.
     
     Parameters
     ----------
     text : str
         Text to parse lines from.
     start : int, optional
         First line to grab from.
     end : int, optional
         Last line to grab from.
     """
     
     # Split the input into lines.
     lines = text.split("\n")
     
     # Return the right lines.
     return "\n".join(lines[start:end]) #re-join
 
 def ipython2python(code):
     """Transform IPython syntax to pure Python syntax
 
     Parameters
     ----------
 
     code : str
         IPython code, to be transformed to pure Python
     """
     shell = InteractiveShell.instance()
     return shell.input_transformer_manager.transform_cell(code)
 
 def posix_path(path):
     """Turn a path into posix-style path/to/etc
     
     Mainly for use in latex on Windows,
     where native Windows paths are not allowed.
     """
     if os.path.sep != '/':
         return path.replace(os.path.sep, '/')
     return path