Merge pull request ipython#29 from ivanov/write-py

added 'py' format, which is cleaner than PyWriter

nbconvert.py

@@ -1180,6 +1180,115 @@ def render_display_format_json(self, output):
     def render_display_format_javascript(self, output):
         return [output.javascript]
 
+class ConverterPy(Converter):
+    """
+    A converter that takes a notebook and converts it to a .py file.
+
+    What distinguishes this from PyWriter and PyReader in IPython.nbformat is
+    that subclasses can specify what to do with each type of cell.
+    Additionally, unlike PyWriter, this does not preserve the '# <markdown>'
+    opening and closing comments style comments in favor of a cleaner looking
+    python program.
+
+    Note:
+        Even though this produces a .py file, it is not guaranteed to be valid
+        python file, since the notebook may be using magics and even cell
+        magics.
+    """
+    extension = 'py'
+
+    def __init__(self, infile, show_prompts=True, show_output=True):
+        super(ConverterPy, self).__init__(infile)
+        self.show_prompts = show_prompts
+        self.show_output = show_output
+
+    @staticmethod
+    def comment(input):
+        "returns every line in input as commented out"
+        return "# "+input.replace("\n", "\n# ")
+
+    @DocInherit
+    def render_heading(self, cell):
+        return ['#{0} {1}'.format('#'*cell.level, cell.source), '']
+
+    @DocInherit
+    def render_code(self, cell):
+        if not cell.input:
+            return []
+        lines = []
+        if self.show_prompts:
+            lines.extend(['# In[%s]:' % cell.prompt_number])
+        src = cell.input
+        lines.extend([src, ''])
+        if self.show_output:
+            if cell.outputs :
+                lines.extend(['# Out[%s]:' % cell.prompt_number])
+            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 [self.comment(cell.source), '']
+
+    @DocInherit
+    def render_raw(self, cell):
+        if self.raw_as_verbatim:
+            return [self.comment(indent(cell.source)), '']
+        else:
+            return [self.comment(cell.source), '']
+
+    @DocInherit
+    def render_pyout(self, output):
+        lines = []
+
+        ## if 'text' in output:
+        ##     lines.extend(['*Out[%s]:*' % output.prompt_number, ''])
+
+        # output is a dictionary like object with type as a key
+        if 'latex' in output:
+            pass
+
+        if 'text' in output:
+            lines.extend([self.comment(indent(output.text)), ''])
+
+        lines.append('')
+        return lines
+
+    @DocInherit
+    def render_pyerr(self, output):
+        # Note: a traceback is a *list* of frames.
+        return [indent(remove_ansi('\n'.join(output.traceback))), '']
+
+    @DocInherit
+    def _img_lines(self, img_file):
+        return [ self.comment('image file: %s' % img_file), '']
+
+    @DocInherit
+    def render_display_format_text(self, output):
+        return [self.comment(indent(output.text))]
+
+    @DocInherit
+    def _unknown_lines(self, data):
+        return [self.comment('Warning: Unknown cell'+ str(data))]
+
+    @DocInherit
+    def render_display_format_html(self, output):
+        return [self.comment(output.html)]
+
+    @DocInherit
+    def render_display_format_latex(self, output):
+        return []
+
+    @DocInherit
+    def render_display_format_json(self, output):
+        return []
+
+    @DocInherit
+    def render_display_format_javascript(self, output):
+        return []
+
 #-----------------------------------------------------------------------------
 # Standalone conversion functions
 #-----------------------------------------------------------------------------
@@ -1316,7 +1425,7 @@ def cell_to_lines(cell):
     return s.split('\n')
 
 
-known_formats = "rst (default), html, quick-html, latex, markdown"
+known_formats = "rst (default), html, quick-html, latex, markdown, py"
 
 def main(infile, format='rst'):
     """Convert a notebook to html in one step"""
@@ -1335,6 +1444,9 @@ def main(infile, format='rst'):
     elif format == 'latex':
         converter = ConverterLaTeX(infile)
         latexfname = converter.render()
+    elif format == 'py':
+        converter = ConverterPy(infile)
+        converter.render()
     else:
         raise SystemExit("Unknown format '%s', " % format +
                 "known formats are: " + known_formats)