Use kernelspec metadata for higlighting in nbconvert

Closes gh-6619

IPython/kernel/kernelspec.py

@@ -123,7 +123,7 b' class KernelSpecManager(HasTraits):'
                'language': 'python',
                'codemirror_mode': {'name': 'ipython',
                                    'version': sys.version_info[0]},
-               'pygments_lexer': 'ipython'
+               'pygments_lexer': 'ipython%d' % (3 if PY3 else 2),
               }
 
     @property

IPython/nbconvert/exporters/html.py

@@ -14,7 +14,7 b''
 
 import os
 
-from IPython.nbconvert import preprocessors
+from IPython.nbconvert.filters.highlight import Highlight2HTML
 from IPython.config import Config
 
 from .templateexporter import TemplateExporter
@@ -57,3 +57,10 b' class HTMLExporter(TemplateExporter):'
             })
         c.merge(super(HTMLExporter,self).default_config)
         return c
+
+    def from_notebook_node(self, nb, resources=None, **kw):
+        kernelspec = nb.metadata.get('kernelspec', {})
+        lexer = kernelspec.get('pygments_lexer', kernelspec.get('language', None))
+        self.register_filter('highlight_code',
+                             Highlight2HTML(pygments_lexer=lexer, parent=self))
+        return super(HTMLExporter, self).from_notebook_node(nb, resources, **kw)

IPython/nbconvert/exporters/latex.py

@@ -19,7 +19,7 b' import os'
 from IPython.utils.traitlets import Unicode
 from IPython.config import Config
 
-from IPython.nbconvert import filters, preprocessors
+from IPython.nbconvert.filters.highlight import Highlight2Latex
 from .templateexporter import TemplateExporter
 
 #-----------------------------------------------------------------------------
@@ -87,3 +87,10 b' class LatexExporter(TemplateExporter):'
          })
         c.merge(super(LatexExporter,self).default_config)
         return c
+
+    def from_notebook_node(self, nb, resources=None, **kw):
+        kernelspec = nb.metadata.get('kernelspec', {})
+        lexer = kernelspec.get('pygments_lexer', kernelspec.get('language', None))
+        self.register_filter('highlight_code',
+                             Highlight2Latex(pygments_lexer=lexer, parent=self))
+        return super(LatexExporter, self).from_notebook_node(nb, resources, **kw)

IPython/nbconvert/filters/highlight.py

@@ -11,6 +11,7 b' from within Jinja templates.'
 # not import time, when it may not be needed.
 
 from IPython.nbconvert.utils.base import NbConvertBase
+from warnings import warn
 
 MULTILINE_OUTPUTS = ['text', 'html', 'svg', 'latex', 'javascript', 'json']
 
@@ -20,6 +21,14 b' __all__ = ['
 ]
 
 class Highlight2HTML(NbConvertBase):
+    def __init__(self, pygments_lexer=None, **kwargs):
+        self.pygments_lexer = pygments_lexer or 'ipython3'
+        super(Highlight2HTML, self).__init__(**kwargs)
+
+    def _default_language_changed(self, name, old, new):
+        warn('Setting default_language in config is deprecated, '
+             'please use kernelspecs instead.')
+        self.pygments_lexer = new
 
     def __call__(self, source, language=None, metadata=None):
         """
@@ -35,8 +44,9 b' class Highlight2HTML(NbConvertBase):'
             metadata of the cell to highlight
         """
         from pygments.formatters import HtmlFormatter
+
         if not language:
-            language=self.default_language
+            language=self.pygments_lexer
 
         return _pygments_highlight(source if len(source) > 0 else ' ',
                                    # needed to help post processors:
@@ -45,6 +55,14 b' class Highlight2HTML(NbConvertBase):'
 
 
 class Highlight2Latex(NbConvertBase):
+    def __init__(self, pygments_lexer=None, **kwargs):
+        self.pygments_lexer = pygments_lexer or 'ipython3'
+        super(Highlight2Latex, self).__init__(**kwargs)
+
+    def _default_language_changed(self, name, old, new):
+        warn('Setting default_language in config is deprecated, '
+             'please use kernelspecs instead.')
+        self.pygments_lexer = new
 
     def __call__(self, source, language=None, metadata=None, strip_verbatim=False):
         """
@@ -63,7 +81,7 b' class Highlight2Latex(NbConvertBase):'
         """
         from pygments.formatters import LatexFormatter
         if not language:
-            language=self.default_language
+            language=self.pygments_lexer
 
         latex = _pygments_highlight(source, LatexFormatter(), language, metadata)
         if strip_verbatim:
@@ -90,7 +108,7 b" def _pygments_highlight(source, output_formatter, language='ipython', metadata=N"
     """
     from pygments import highlight
     from pygments.lexers import get_lexer_by_name
-    from IPython.nbconvert.utils.lexers import IPythonLexer
+    from IPython.nbconvert.utils.lexers import IPythonLexer, IPython3Lexer
 
     # If the cell uses a magic extension language,
     # use the magic language instead.
@@ -100,8 +118,10 b" def _pygments_highlight(source, output_formatter, language='ipython', metadata=N"
 
         language = metadata['magics_language']
 
-    if language == 'ipython':
+    if language == 'ipython2':
         lexer = IPythonLexer()
+    elif language == 'ipython3':
+        lexer = IPython3Lexer()
     else:
         lexer = get_lexer_by_name(language, stripall=True)
 

IPython/nbconvert/filters/tests/test_highlight.py

@@ -25,9 +25,7 b' import xml'
 
 highlight2html = Highlight2HTML()
 highlight2latex = Highlight2Latex()
-c = Config()
-c.Highlight2HTML.default_language='ruby'
-highlight2html_ruby = Highlight2HTML(config=c)
+highlight2html_ruby = Highlight2HTML(pygments_lexer='ruby')
 
 class TestHighlight(TestsBase):
     """Contains test functions for highlight.py"""
@@ -37,8 +35,10 b' class TestHighlight(TestsBase):'
         """
         #Hello World Example
 
+        import foo
+
         def say(text):
-            print(text)
+            foo.bar(text)
 
         end
 
@@ -51,7 +51,7 b' class TestHighlight(TestsBase):'
         ]   
 
     tokens = [
-        ['Hello World Example', 'say', 'text', 'print', 'def'],
+        ['Hello World Example', 'say', 'text', 'import', 'def'],
         ['pylab', 'plot']]
 
 
@@ -72,11 +72,13 b' class TestHighlight(TestsBase):'
         rb =  highlight2html_ruby(self.tests[0])
 
         for lang,tkns in [
-                ( ht, ('def','print') ),
+                ( ht, ('def', )),
                 ( rb, ('def','end'  ) )
                 ]:
+            print(tkns)
+            print(lang)
             root = xml.etree.ElementTree.fromstring(lang)
-            assert self._extract_tokens(root,'k') == set(tkns)
+            self.assertEqual(self._extract_tokens(root,'k'), set(tkns))
 
     def _extract_tokens(self, root, cls):
         return set(map(lambda x:x.text,root.findall(".//*[@class='"+cls+"']")))

IPython/nbconvert/templates/html/basic.tpl

@@ -46,7 +46,7 b' In [ ]:'
 {% block input %}
 <div class="inner_cell">
     <div class="input_area">
-{{ cell.input | highlight2html(language=resources.get('language'), metadata=cell.metadata) }}
+{{ cell.input | highlight_code(metadata=cell.metadata) }}
 </div>
 </div>
 {%- endblock input %}

IPython/nbconvert/templates/latex/style_ipython.tplx

@@ -20,7 +20,7 b''
 %===============================================================================
 
 ((* block input scoped *))
-    ((( add_prompt(cell.input | highlight2latex(strip_verbatim=True), cell, 'In ', 'incolor') )))
+    ((( add_prompt(cell.input | highlight_code(strip_verbatim=True), cell, 'In ', 'incolor') )))
 ((* endblock input *))
 
 

IPython/nbconvert/templates/latex/style_python.tplx

@@ -16,6 +16,6 b''
 
 ((* block input scoped *))
     \begin{Verbatim}[commandchars=\\\{\}]
-((( cell.input | highlight2latex(language=resources.get('language'), strip_verbatim=True) | add_prompts )))
+((( cell.input | highlight_code(strip_verbatim=True) | add_prompts )))
     \end{Verbatim}
 ((* endblock input *))