upstream/ipython Files · IPython/nbconvert/exporters/markdown.py

Reset the interactive namespace __warningregistry__ before executing code...

Reset the interactive namespace __warningregistry__ before executing code Fixes . Idea: Right now, people often don't see important warnings when running code in IPython, because (to a first approximation) any given warning will only issue once per session. Blink and you'll miss it! This is a very common contributor to confused emails to numpy-discussion. E.g.: In [5]: 1 / my_array_with_random_contents /home/njs/.user-python2.7-64bit-3/bin/ipython:1: RuntimeWarning: divide by zero encountered in divide #!/home/njs/.user-python2.7-64bit-3/bin/python Out[5]: array([ 1.77073316, -2.29765021, -2.01800811, ..., 1.13871243, -1.08302964, -8.6185091 ]) Oo, right, guess I gotta be careful of those zeros -- thanks, numpy, for giving me that warning! A few days later: In [592]: 1 / some_other_array Out[592]: array([ 3.07735763, 0.50769289, 0.83984078, ..., -0.67563917, -0.85736257, -1.36511271]) Oops, it turns out that this array had a zero in it too, and that's going to bite me later. But no warning this time! The effect of this commit is to make it so that warnings triggered by the code in cell 5 do *not* suppress warnings triggered by the code in cell 592. Note that this only applies to warnings triggered *directly* by code entered interactively -- if somepkg.foo() calls anotherpkg.bad_func() which issues a warning, then this warning will still only be displayed once, even if multiple cells call somepkg.foo(). But if cell 5 and cell 592 both call anotherpkg.bad_func() directly, then both will get warnings. (Important exception: if foo() is defined *interactively*, and calls anotherpkg.bad_func(), then every cell that calls foo() will display the warning again. This is unavoidable without fixes to CPython upstream.) Explanation: Python's warning system has some weird quirks. By default, it tries to suppress duplicate warnings, where "duplicate" means the same warning message triggered twice by the same line of code. This requires determining which line of code is responsible for triggering a warning, and this is controlled by the stacklevel= argument to warnings.warn. Basically, though, the idea is that if foo() calls bar() which calls baz() which calls some_deprecated_api(), then baz() will get counted as being "responsible", and the warning system will make a note that the usage of some_deprecated_api() inside baz() has already been warned about and doesn't need to be warned about again. So far so good. To accomplish this, obviously, there has to be a record of somewhere which line this was. You might think that this would be done by recording the filename:linenumber pair in a dict inside the warnings module, or something like that. You would be wrong. What actually happens is that the warnings module will use stack introspection to reach into baz()'s execution environment, create a global (module-level) variable there named __warningregistry__, and then, inside this dictionary, record just the line number. Basically, it assumes that any given module contains only one line 1, only one line 2, etc., so storing the filename is irrelevant. Obviously for interactive code this is totally wrong -- all cells share the same execution environment and global namespace, and they all contain a new line 1. Currently the warnings module treats these as if they were all the same line. In fact they are not the same line; once we have executed a given chunk of code, we will never see those particular lines again. As soon as a given chunk of code finishes executing, its line number labels become meaningless, and the corresponding warning registry entries become meaningless as well. Therefore, with this patch we delete the __warningregistry__ each time we execute a new block of code.

Thomas Kluyver - - Load All Authors

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             / IPython / nbconvert / exporters / markdown.py
          
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        MinRK
    
add raw_format to Exporter classes...

              r13664
            
      """Markdown Exporter class"""

        Jonathan Frederic
    
Finished a rough draft of the exporters.

              r10588
            
      #-----------------------------------------------------------------------------

      # 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

      #-----------------------------------------------------------------------------

        MinRK
    
fix markdown images...

              r12451
            
      from IPython.config import Config

        Jonathan Frederic
    
Cleanup and refactor of API, almost complete....

              r10677
            
        Jonathan Frederic
    
Rebase changes made by hand

              r12505
            
      from .templateexporter import TemplateExporter

        Jonathan Frederic
    
Finished a rough draft of the exporters.

              r10588
            
      #-----------------------------------------------------------------------------

      # Classes

      #-----------------------------------------------------------------------------

        Matthias BUSSONNIER
    
Exporter -> TemplateExporter / BaseExporter

              r12500
            
      class MarkdownExporter(TemplateExporter):

        Jonathan Frederic
    
Cleanup and refactor of API, almost complete....

              r10677
            
          """

          Exports to a markdown document (.md)

          """

        Thomas Kluyver
    
Remove magic for loading templates from module names

              r13925
            
          def _file_extension_default(self):

              return 'md'

          def _template_file_default(self):

              return 'markdown'

        MinRK
    
fix markdown images...

              r12451
            
        Thomas Kluyver
    
Make output_mimetype accessible from the class....

              r13834
            
          output_mimetype = 'text/markdown'

        MinRK
    
add raw_format to Exporter classes...

              r13664
            
        MinRK
    
propagate raw_mimetype to nbconvert

              r13678
            
          def _raw_mimetypes_default(self):

        Thomas Kluyver
    
Condense raw_mimetype and mime_type traitlets into output_mimetype

              r13832
            
              return ['text/markdown', 'text/html', '']

        Thomas Kluyver
    
Add MIME types to nbconvert exporters

              r13830
            
        MinRK
    
fix markdown images...

              r12451
            
          @property

          def default_config(self):

              c = Config({'ExtractOutputPreprocessor':{'enabled':True}})

              c.merge(super(MarkdownExporter,self).default_config)

              return c

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MinRK add raw_format to Exporter classes...	r13664	"""Markdown Exporter class"""

Jonathan Frederic Finished a rough draft of the exporters.	r10588	#-----------------------------------------------------------------------------
		# 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
		#-----------------------------------------------------------------------------

MinRK fix markdown images...	r12451	from IPython.config import Config
Jonathan Frederic Cleanup and refactor of API, almost complete....	r10677
Jonathan Frederic Rebase changes made by hand	r12505	from .templateexporter import TemplateExporter
Jonathan Frederic Finished a rough draft of the exporters.	r10588
		#-----------------------------------------------------------------------------
		# Classes
		#-----------------------------------------------------------------------------

Matthias BUSSONNIER Exporter -> TemplateExporter / BaseExporter	r12500	class MarkdownExporter(TemplateExporter):
Jonathan Frederic Cleanup and refactor of API, almost complete....	r10677	"""
		Exports to a markdown document (.md)
		"""

Thomas Kluyver Remove magic for loading templates from module names	r13925	def _file_extension_default(self):
		return 'md'

		def _template_file_default(self):
		return 'markdown'
MinRK fix markdown images...	r12451
Thomas Kluyver Make output_mimetype accessible from the class....	r13834	output_mimetype = 'text/markdown'
MinRK add raw_format to Exporter classes...	r13664
MinRK propagate raw_mimetype to nbconvert	r13678	def _raw_mimetypes_default(self):
Thomas Kluyver Condense raw_mimetype and mime_type traitlets into output_mimetype	r13832	return ['text/markdown', 'text/html', '']
Thomas Kluyver Add MIME types to nbconvert exporters	r13830
MinRK fix markdown images...	r12451	@property
		def default_config(self):
		c = Config({'ExtractOutputPreprocessor':{'enabled':True}})
		c.merge(super(MarkdownExporter,self).default_config)
		return c