allow extra pandoc args

IPython/nbconvert/filters/strings.py

@@ -1,116 +1,123 b''
 """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 re
 import textwrap
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 __all__ = [
     'wrap',
     'strip_dollars',
     'rm_fake',
     'python_comment',
     'get_lines'
 ]
 
 
 def wrap(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 single_line(text):
+    """Wrap multi-line text into a single line
+    
+    Used in markdown heading cells, which are not allowed to be multiline.
+    """
+    return ''.join(text.splitlines())
+
 
 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 rm_fake(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 python_comment(text):
     """
     Build a Python comment line from input text.
     
     Parameters
     ----------
     text : str
         Text to comment out.
     """
     
     #Replace line breaks with line breaks and comment symbols.
     #Also add a comment symbol at the beginning to comment out
     #the first line.
     return '# '+'\n# '.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

IPython/nbconvert/utils/pandoc.py

@@ -1,53 +1,56 b''
 """Utility for calling pandoc"""
 #-----------------------------------------------------------------------------
 # 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 __future__ import print_function
 
 # Stdlib imports
 import sys
 import subprocess
 
 # IPython imports
 from IPython.utils.py3compat import cast_bytes
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
-def pandoc(source, fmt, to, encoding='utf-8'):
+def pandoc(source, fmt, to, extra_args=None, encoding='utf-8'):
     """Convert an input string in format `from` to format `to` via pandoc.
 
     This function will raise an error if pandoc is not installed.
     Any error messages generated by pandoc are printed to stderr.
 
     Parameters
     ----------
     source : string
       Input string, assumed to be valid format `from`.
     fmt : string
       The name of the input format (markdown, etc.)
     to : string
       The name of the output format (html, etc.)
 
     Returns
     -------
     out : unicode
       Output as returned by pandoc.
     """
-    p = subprocess.Popen(['pandoc', '-f', fmt, '-t', to],
+    command = ['pandoc', '-f', fmt, '-t', to]
+    if extra_args:
+        command = command + extra_args
+    p = subprocess.Popen(command,
                          stdin=subprocess.PIPE, stdout=subprocess.PIPE
     )
     out, _ = p.communicate(cast_bytes(source, encoding))
     out = out.decode(encoding, 'replace')
     return out[:-1]