make render_heading reusable

nbconvert.py

@@ -1,270 +1,270 b''
 #!/usr/bin/env python
 """A really simple notebook to rst/html exporter.
 
 Usage
 
   ./nb2html.py file.ipynb
 
 Produces 'file.rst' and 'file.html', along with auto-generated figure files
 called nb_figure_NN.png.
 
 """
 
 import os
 import subprocess
 import sys
 from IPython.external import argparse
 from IPython.nbformat import current as nbformat
 from IPython.utils.text import indent
 
 
 # Cell converters
 
 def unknown_cell(cell):
     """Default converter for cells of unknown type.
     """
 
     return rst_directive('.. warning:: Unknown cell') + \
       [repr(cell)]
 
 
 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'
 
     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""")
 
     def dispatch(self, cell_type):
         """return cell_type dependent render method,  for example render_code
         """
         return getattr(self, 'render_' + cell_type, unknown_cell)
 
     def convert(self):
         lines = []
         for cell in self.nb.worksheets[0].cells:
             conv_fn = self.dispatch(cell.cell_type)
             lines.extend(conv_fn(cell))
             lines.append('')
         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 render_heading(self, cell):
         raise NotImplementedError
 
     def render_code(self, cell):
         raise NotImplementedError
 
     def render_markdown(self, cell):
         raise NotImplementedError
 
     def render_pyout(self, cell):
         raise NotImplementedError
 
     def render_display_data(self, cell):
         raise NotImplementedError
 
     def render_stream(self, cell):
         raise NotImplementedError
 
 
 class ConverterRST(Converter):
     extension = 'rst'
     figures_counter = 0
+    heading_level = {1: '=', 2: '-', 3: '`', 4: '\'', 5: '.', 6: '~'}
 
     def render_heading(self, cell):
         """convert a heading cell to rst
 
         Returns list."""
-        heading_level = {1: '=', 2: '-', 3: '`', 4: '\'', 5: '.', 6: '~'}
-        marker = heading_level[cell.level]
+        marker = self.heading_level[cell.level]
         return ['{0}\n{1}\n'.format(cell.source, marker * len(cell.source))]
 
     def render_code(self, cell):
         """Convert a code cell to rst
 
         Returns list."""
 
         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
 
     def render_markdown(self, cell):
         """convert a markdown cell to rst
 
         Returns list."""
         return [cell.source]
 
     def render_plaintext(self, cell):
         """convert plain text to rst
 
         Returns list."""
         return [cell.source]
 
     def render_pyout(self, output):
         """convert pyout part of a code cell to rst
 
         Returns list."""
 
         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
 
     def render_display_data(self, output):
         """convert display data from the output of a code cell to rst.
 
         Returns list.
         """
         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('.. image:: %s' % infile)
             lines.append('')
 
         return lines
 
     def render_stream(self, output):
         """convert stream part of a code cell to rst
 
         Returns list."""
 
         lines = []
 
         if 'text' in output:
             lines.extend(rst_directive('.. parsed-literal::', output.text))
 
         return lines
 
 
 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
 
 
 def main(infile, format='rst'):
     """Convert a notebook to html in one step"""
     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)
 
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description='nbconvert: Convert IPython notebooks to other formats')
 
     # 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')
     args = parser.parse_args()
     main(infile=args.infile[0], format=args.format)

tests/test_simple.py

@@ -1,70 +1,69 b''
 from nbconvert import ConverterRST, main
 import nose.tools as nt
 
 import os
 import glob
 from IPython.nbformat import current as nbformat
 
 fname = 'tests/test.ipynb'
 out_fname = 'tests/test.rst'
 
 
 def clean_dir():
     "Remove .rst files created during conversion"
     map(os.remove, glob.glob("./tests/*.rst"))
     map(os.remove, glob.glob("./tests/*.png"))
     map(os.remove, glob.glob("./tests/*.html"))
 
 
 @nt.with_setup(clean_dir, clean_dir)
 def test_simple():
     c = ConverterRST(fname)
     f = c.render()
     nt.assert_true('rst' in f, 'changed file extension to rst')
 
 
 @nt.with_setup(clean_dir, clean_dir)
 def test_main():
     """
     Test main entry point
     """
     main(fname)
     nt.assert_true(os.path.exists(out_fname))
 
 
 def test_render_heading():
     """ Unit test for cell type "heading" """
     # Generate and test heading cells level 1-6
     for level in xrange(1, 7):
         cell = {
             'cell_type': 'heading',
             'level'    : level,
             'source'   :  ['Test for heading type H{0}'.format(level)]
             }
         # Convert cell dictionaries to NotebookNode
         cell_nb = nbformat.NotebookNode(cell)
         # Make sure "source" attribute is uniconde not list.
         # For some reason, creating a NotebookNode manually like
         # this isn't converting source to a string like using
         # the create-from-file routine.
         if type(cell_nb.source) is list:
             cell_nb.source = '\n'.join(cell_nb.source)
         # Render to rst
         c = ConverterRST('')
         rst_list = c.render_heading(cell_nb)
         nt.assert_true(isinstance(rst_list, list))  # render should return a list
         rst_str = "".join(rst_list)
         # Confirm rst content
-        heading_level = {1: '=', 2: '-', 3: '`', 4: '\'', 5: '.', 6: '~'}
         chk_str = "Test for heading type H{0}\n{1}\n".format(
-             level, heading_level[level] * 24)
+             level, c.heading_level[level] * 24)
         nt.assert_equal(rst_str, chk_str)
 
 
 @nt.with_setup(clean_dir, clean_dir)
 def test_main_html():
     """
     Test main entry point
     """
     main(fname, format='html')
     nt.assert_true(os.path.exists('tests/test.html'))