Improve SVG support, other small fixes.

nbconvert.py

@@ -1,557 +1,595 b''
 #!/usr/bin/env python
 """Convert IPython notebooks to other formats, such as ReST, and HTML.
 
 Example:
   ./nbconvert.py --format html file.ipynb
 
 Produces 'file.rst' and 'file.html', along with auto-generated figure files
 called nb_figure_NN.png. To avoid the two-step process, ipynb -> rst -> html,
 use '--format quick-html' which will do ipynb -> html, but won't look as
 pretty.
 """
 from __future__ import print_function
 
+import codecs
 import os
 import pprint
 import re
 import subprocess
 import sys
 
 from IPython.external import argparse
 from IPython.nbformat import current as nbformat
 from IPython.utils.text import indent
 from decorators import DocInherit
 
 def remove_ansi(src):
     """Strip all ANSI color escape sequences from input string.
 
     Parameters
     ----------
     src : string
 
     Returns
     -------
     string
     """
     return re.sub(r'\033\[(0|\d;\d\d)m', '', src)
 
 # Pandoc-dependent code
 def markdown2latex(src):
     """Convert a markdown string to LaTeX via pandoc.
 
     This function will raise an error if pandoc is not installed.
 
     Any error messages generated by pandoc are printed to stderr.
 
     Parameters
     ----------
     src : string
       Input string, assumed to be valid markdown.
 
     Returns
     -------
     out : string
       Output as returned by pandoc.
     """
     p = subprocess.Popen('pandoc -f markdown -t latex'.split(),
                          stdin=subprocess.PIPE, stdout=subprocess.PIPE)
     out, err = p.communicate(src)
     if err:
         print(err, file=sys.stderr)
     #print('*'*20+'\n', out, '\n'+'*'*20)  # dbg
     return out
 
 # Cell converters
 
 
 def rst_directive(directive, text=''):
     out = [directive, '']
     if text:
         out.extend([indent(text), ''])
     return out
 
 # Converters for parts of a cell.
 
 
 class ConversionException(Exception):
     pass
 
 
 class Converter(object):
     default_encoding = 'utf-8'
+    extension = str()
     figures_counter = 0
-
+    infile = str()
+    infile_dir = str()
+    infile_root = str()
+    files_dir = str()
+    
     def __init__(self, infile):
         self.infile = infile
-        self.dirpath = os.path.dirname(infile)
-
-    @property
-    def extension(self):
-        raise ConversionException("""extension must be defined in Converter
-                subclass""")
+        self.infile_dir = os.path.dirname(infile)
+        infile_root = os.path.splitext(infile)[0]
+        files_dir = infile_root + '_files'
+        if not os.path.isdir(files_dir):
+            os.mkdir(files_dir)
+        self.infile_root = infile_root
+        self.files_dir = files_dir
 
     def dispatch(self, cell_type):
         """return cell_type dependent render method,  for example render_code
         """
         return getattr(self, 'render_' + cell_type, self.render_unknown)
 
     def convert(self):
         lines = []
         lines.extend(self.optional_header())
         for worksheet in self.nb.worksheets:
             for cell in worksheet.cells:
                 conv_fn = self.dispatch(cell.cell_type)
                 lines.extend(conv_fn(cell))
                 lines.append('')
         lines.extend(self.optional_footer())
         return '\n'.join(lines)
 
     def render(self):
         "read, convert, and save self.infile"
         self.read()
         self.output = self.convert()
         return self.save()
 
     def read(self):
         "read and parse notebook into NotebookNode called self.nb"
         with open(self.infile) as f:
             self.nb = nbformat.read(f, 'json')
 
     def save(self, infile=None, encoding=None):
         "read and parse notebook into self.nb"
         if infile is None:
             infile = os.path.splitext(self.infile)[0] + '.' + self.extension
         if encoding is None:
             encoding = self.default_encoding
         with open(infile, 'w') as f:
             f.write(self.output.encode(encoding))
         return infile
 
     def optional_header(self):
         return []
 
     def optional_footer(self):
         return []
 
-    def _new_figure(self, data, format):
-        basename = self.infile.replace('.ipynb', '')
-        figname = '%s_fig_%02i.%s' % (basename, self.figures_counter, format)
+    def _new_figure(self, data, fmt):
+        """Create a new figure file in the given format.
+
+        Returns a path relative to the input file.
+        """
+        figname = '%s_fig_%02i.%s' % (self.infile_root, 
+                                      self.figures_counter, fmt)
         self.figures_counter += 1
-        fullname = os.path.join(self.dirpath, figname)
-        with open(fullname, 'w') as f:
-            f.write(data.decode('base64'))
-        return figname
+        fullname = os.path.join(self.files_dir, figname)
+
+        # Binary files are base64-encoded, SVG is already XML
+        if fmt in ('png', 'jpg', 'pdf'):
+            data = data.decode('base64')
+            fopen = lambda fname: open(fname, 'wb')
+        else:
+            fopen = lambda fname: codecs.open(fname, 'wb', self.default_encoding)
+            
+        with fopen(fullname) as f:
+            f.write(data)
+            
+        return fullname
 
     def render_heading(self, cell):
         """convert a heading cell
 
         Returns list."""
         raise NotImplementedError
 
     def render_code(self, cell):
         """Convert a code cell
 
         Returns list."""
         raise NotImplementedError
 
     def render_markdown(self, cell):
         """convert a markdown cell
 
         Returns list."""
         raise NotImplementedError
 
     def render_pyout(self, output):
         """convert pyout part of a code cell
 
         Returns list."""
         raise NotImplementedError
 
 
     def render_pyerr(self, output):
         """convert pyerr part of a code cell
 
         Returns list."""
         raise NotImplementedError
 
+    def _img_lines(self, img_file):
+        """Return list of lines to include an image file."""
+        # Note: subclasses may choose to implement format-specific _FMT_lines
+        # methods if they so choose (FMT in {png, svg, jpg, pdf}).
+        raise NotImplementedError
+
     def render_display_data(self, output):
         """convert display data from the output of a code cell
 
         Returns list.
         """
-        raise NotImplementedError
+        lines = []
+
+        for fmt in ['png', 'svg', 'jpg', 'pdf']:
+            if fmt in output:
+                img_file = self._new_figure(output[fmt], fmt)
+                # Subclasses can have format-specific render functions (e.g.,
+                # latex has to auto-convert all SVG to PDF first).
+                lines_fun = getattr(self, '_%s_lines' % fmt, None)
+                if not lines_fun:
+                    lines_fun = self._img_lines
+                lines.extend(lines_fun(img_file))
+
+        return lines
 
     def render_stream(self, cell):
         """convert stream part of a code cell
 
         Returns list."""
         raise NotImplementedError
 
     def render_plaintext(self, cell):
         """convert plain text
 
         Returns list."""
         raise NotImplementedError
 
     def render_unknown(self, cell):
         """Render cells of unkown type
 
         Returns list."""
         raise NotImplementedError
 
 
 class ConverterRST(Converter):
     extension = 'rst'
     heading_level = {1: '=', 2: '-', 3: '`', 4: '\'', 5: '.', 6: '~'}
 
     @DocInherit
     def render_heading(self, cell):
         marker = self.heading_level[cell.level]
         return ['{0}\n{1}\n'.format(cell.source, marker * len(cell.source))]
 
     @DocInherit
     def render_code(self, cell):
         if not cell.input:
             return []
 
         lines = ['In[%s]:' % cell.prompt_number, '']
         lines.extend(rst_directive('.. code:: python', cell.input))
 
         for output in cell.outputs:
             conv_fn = self.dispatch(output.output_type)
             lines.extend(conv_fn(output))
 
         return lines
 
     @DocInherit
     def render_markdown(self, cell):
         return [cell.source]
 
     @DocInherit
     def render_plaintext(self, cell):
         return [cell.source]
 
     @DocInherit
     def render_pyout(self, output):
         lines = ['Out[%s]:' % output.prompt_number, '']
 
         # output is a dictionary like object with type as a key
         if 'latex' in output:
             lines.extend(rst_directive('.. math::', output.latex))
 
         if 'text' in output:
             lines.extend(rst_directive('.. parsed-literal::', output.text))
 
         return lines
 
     @DocInherit
-    def render_display_data(self, output):
-        lines = []
-
-        if 'png' in output:
-            figfile = self._new_figure(output.png, 'png')
-            lines.append('.. image:: %s' % figfile)
-            lines.append('')
-
-        return lines
-
+    def _img_lines(self, img_file):
+        return ['.. image:: %s' % figfile, '']
+    
     @DocInherit
     def render_stream(self, output):
         lines = []
 
         if 'text' in output:
             lines.extend(rst_directive('.. parsed-literal::', output.text))
 
         return lines
 
     @DocInherit
     def render_unknown(self, cell):
         return rst_directive('.. warning:: Unknown cell') + [repr(cell)]
 
 class ConverterQuickHTML(Converter):
     extension = 'html'
 
     def optional_header(self):
         # XXX: inject the IPython standard CSS into here
         s = """<html>
         <head>
         </head>
 
         <body>
         """
         return s.splitlines()
 
     def optional_footer(self):
         s = """</body>
         </html>
         """
         return s.splitlines()
 
     @DocInherit
     def render_heading(self, cell):
         marker = cell.level
         return ['<h{1}>\n  {0}\n</h{1}>'.format(cell.source, marker)]
 
     @DocInherit
     def render_code(self, cell):
         if not cell.input:
             return []
 
         lines = ['<table>']
         lines.append('<tr><td><tt>In [<b>%s</b>]:</tt></td><td><tt>' % cell.prompt_number)
         lines.append("<br>\n".join(cell.input.splitlines()))
         lines.append('</tt></td></tr>')
 
         for output in cell.outputs:
             lines.append('<tr><td></td><td>')
             conv_fn = self.dispatch(output.output_type)
             lines.extend(conv_fn(output))
             lines.append('</td></tr>')
         
         lines.append('</table>')
         return lines
 
     @DocInherit
     def render_markdown(self, cell):
         return ["<pre>"+cell.source+"</pre>"]
 
     @DocInherit
     def render_plaintext(self, cell):
         return ["<pre>"+cell.source+"</pre>"]
 
     @DocInherit
     def render_pyout(self, output):
         lines = ['<tr><td><tt>Out[<b>%s</b>]:</tt></td></tr>' % output.prompt_number, '<td>']
 
         # output is a dictionary like object with type as a key
         if 'latex' in output:
             lines.append("<pre>")
             lines.extend(indent(output.latex))
             lines.append("</pre>")
 
         if 'text' in output:
             lines.append("<pre>")
             lines.extend(indent(output.text))
             lines.append("</pre>")
 
         return lines
 
     @DocInherit
-    def render_display_data(self, output):
-        lines = []
-
-        if 'png' in output:
-            infile = 'nb_figure_%s.png' % self.figures_counter
-            fullname = os.path.join(self.dirpath, infile)
-            with open(fullname, 'w') as f:
-                f.write(output.png.decode('base64'))
-
-            self.figures_counter += 1
-            lines.append('<img src="%s">' % infile)
-            lines.append('')
-
-        return lines
+    def _img_lines(self, img_file):
+        return ['<img src="%s">' % img_file, '']
 
     @DocInherit
     def render_stream(self, output):
         lines = []
 
         if 'text' in output:
             lines.append(output.text)
 
         return lines
 
 
 class ConverterLaTeX(Converter):
+    """Converts a notebook to a .tex file suitable for pdflatex.
+
+    Note: this converter *needs*:
+
+    - `pandoc`: for all conversion of markdown cells.  If your notebook only
+       has Raw cells, pandoc will not be needed.
+    
+    -  `inkscape`: if your notebook has SVG figures.  These need to be
+       converted to PDF before inclusion in the TeX file, as LaTeX doesn't
+       understand SVG natively.
+    
+    You will in general obtain much better final PDF results if you configure
+    the matplotlib backend to create SVG output with 
+
+    %config InlineBackend.figure_format = 'svg'
+
+    (or set the equivalent flag at startup or in your configuration profile).
+    """
     extension = 'tex'
+    heading_marker = {1: r'\section',
+                      2: r'\subsection',
+                      3: r'\subsubsection',
+                      4: r'\paragraph',
+                      5: r'\subparagraph',
+                      6: r'\subparagraph'}
 
     def env(self, environment, lines):
         """Return list of environment lines for input lines
 
         Parameters
         ----------
         env : string
           Name of the environment to bracket with begin/end.
 
         lines: """
         out = [r'\begin{%s}' % environment]
         if isinstance(lines, basestring):
             out.append(lines)
         else:  # list
             out.extend(lines)
         out.append(r'\end{%s}' % environment)
         return out
     
     @DocInherit
     def render_heading(self, cell):
-        heading_marker = {1: r'\section',
-                          2: r'\subsection',
-                          3: r'\subsubsection',
-                          4: r'\paragraph',
-                          5: r'\subparagraph',
-                          6: r'\subparagraph'}
-        marker = heading_marker[cell.level]
+        marker = self.heading_marker[cell.level]
         return ['%s{%s}\n\n' % (marker, cell.source) ]
 
     @DocInherit
     def render_code(self, cell):
         if not cell.input:
             return []
 
         # Cell codes first carry input code, we use lstlisting for that
         lines = [r'\begin{codecell}']
         
         lines.extend(self.env('codeinput',
                               self.env('lstlisting', cell.input)))
 
         outlines = []
         for output in cell.outputs:
             conv_fn = self.dispatch(output.output_type)
             outlines.extend(conv_fn(output))
 
         # And then output of many possible types; use a frame for all of it.
         if outlines:
             lines.extend(self.env('codeoutput', outlines))
 
         lines.append(r'\end{codecell}')
 
         return lines
 
-    @DocInherit
-    def render_display_data(self, output):
-        lines = []
-
-        if 'png' in output:
-            figfile = self._new_figure(output.png, 'png')
 
-            lines.extend(self.env('center',
-                                  [r'\includegraphics[width=3in]{%s}' % figfile,
-                                   r'\par']))
-        return lines
+    @DocInherit
+    def _img_lines(self, img_file):
+        return self.env('center',
+                [r'\includegraphics[width=3in]{%s}' % img_file, r'\par'])
+
+    def _svg_lines(self, img_file):
+        base_file = os.path.splitext(img_file)[0]
+        pdf_file = base_file + '.pdf'
+        subprocess.check_call(['inkscape', '--export-pdf=%s' % pdf_file,
+                               img_file])
+        return self._img_lines(pdf_file)
 
     @DocInherit
     def render_stream(self, output):
         lines = []
 
         if 'text' in output:
             lines.extend(self.env('verbatim', output.text.strip()))
 
         return lines
 
     @DocInherit
     def render_markdown(self, cell):
         return [markdown2latex(cell['source'])]
         
     @DocInherit
     def render_pyout(self, output):
         lines = []
 
         # output is a dictionary like object with type as a key
         if 'latex' in output:
             lines.extend(output.latex)
 
         if 'text' in output:
             lines.extend(self.env('verbatim', output.text))
 
         return lines
 
     @DocInherit
     def render_pyerr(self, output):
         # Note: a traceback is a *list* of frames.
         return self.env('traceback',
                         self.env('verbatim', 
                                  remove_ansi('\n'.join(output.traceback))))
 
     @DocInherit
     def render_unknown(self, cell):
         return self.env('verbatim', pprint.pformat(cell))
 
 
 def rst2simplehtml(infile):
     """Convert a rst file to simplified html suitable for blogger.
 
     This just runs rst2html with certain parameters to produce really simple
     html and strips the document header, so the resulting file can be easily
     pasted into a blogger edit window.
     """
 
     # This is the template for the rst2html call that produces the cleanest,
     # simplest html I could find.  This should help in making it easier to
     # paste into the blogspot html window, though I'm still having problems
     # with linebreaks there...
     cmd_template = ("rst2html --link-stylesheet --no-xml-declaration "
                     "--no-generator --no-datestamp --no-source-link "
                     "--no-toc-backlinks --no-section-numbering "
                     "--strip-comments ")
 
     cmd = "%s %s" % (cmd_template, infile)
     proc = subprocess.Popen(cmd,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE,
                             shell=True)
     html, stderr = proc.communicate()
     if stderr:
         raise IOError(stderr)
 
     # Make an iterator so breaking out holds state.  Our implementation of
     # searching for the html body below is basically a trivial little state
     # machine, so we need this.
     walker = iter(html.splitlines())
 
     # Find start of main text, break out to then print until we find end /div.
     # This may only work if there's a real title defined so we get a 'div class'
     # tag, I haven't really tried.
     for line in walker:
         if line.startswith('<body>'):
             break
 
     newfname = os.path.splitext(infile)[0] + '.html'
     with open(newfname, 'w') as f:
         for line in walker:
             if line.startswith('</body>'):
                 break
             f.write(line)
             f.write('\n')
 
     return newfname
 
 known_formats = "rst (default), html, quick-html, latex"
 
 def main(infile, format='rst'):
     """Convert a notebook to html in one step"""
     # XXX: this is just quick and dirty for now. When adding a new format,
     # make sure to add it to the `known_formats` string above, which gets
     # printed in in the catch-all else, as well as in the help
     if format == 'rst':
         converter = ConverterRST(infile)
         converter.render()
     elif format == 'html':
         #Currently, conversion to html is a 2 step process, nb->rst->html
         converter = ConverterRST(infile)
         rstfname = converter.render()
         rst2simplehtml(rstfname)
     elif format == 'quick-html':
         converter = ConverterQuickHTML(infile)
         rstfname = converter.render()
     elif format == 'latex':
         converter = ConverterLaTeX(infile)
         latexfname = converter.render()
     else:
         raise SystemExit("Unknown format '%s', " % format +
                 "known formats are: " + known_formats)
 
 
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description=__doc__,
             formatter_class=argparse.RawTextHelpFormatter)
     # TODO: consider passing file like object around, rather than filenames
     # would allow us to process stdin, or even http streams
     #parser.add_argument('infile', nargs='?', type=argparse.FileType('r'), default=sys.stdin)
 
     #Require a filename as a positional argument
     parser.add_argument('infile', nargs=1)
     parser.add_argument('-f', '--format', default='rst',
                         help='Output format. Supported formats: \n' +
                         known_formats)
     args = parser.parse_args()
     main(infile=args.infile[0], format=args.format)