Catch ConversionExceptions in main nbconvert loop

IPython/nbconvert/nbconvertapp.py

@@ -1,226 +1,235 b''
 #!/usr/bin/env python
 """NBConvert is a utility for conversion of .ipynb files.
 
 Command-line interface for the NbConvert conversion utility.
 """
 #-----------------------------------------------------------------------------
 #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
 #-----------------------------------------------------------------------------
 
 # Stdlib imports
 from __future__ import print_function
 import sys
 import os
 import glob
 
 # From IPython
 from IPython.core.application import BaseIPythonApplication, base_aliases, base_flags
 from IPython.config import catch_config_error, Configurable
 from IPython.utils.traitlets import (
     Unicode, List, Instance, DottedObjectName, Type, CaselessStrEnum,
 )
 from IPython.utils.importstring import import_item
 
 from .exporters.export import export_by_name, get_export_names, ExporterNameError
 from IPython.nbconvert import exporters, transformers, writers
 from .utils.base import NbConvertBase
+from .utils.exceptions import ConversionException
 
 #-----------------------------------------------------------------------------
 #Classes and functions
 #-----------------------------------------------------------------------------
 
 nbconvert_aliases = {}
 nbconvert_aliases.update(base_aliases)
 nbconvert_aliases.update({
     'format' : 'NbConvertApp.export_format',
     'notebooks' : 'NbConvertApp.notebooks',
     'writer' : 'NbConvertApp.writer_class',
 })
 
 nbconvert_flags = {}
 nbconvert_flags.update(base_flags)
 nbconvert_flags.update({
     'stdout' : (
         {'NbConvertApp' : {'writer_class' : "StdoutWriter"}},
         "Write notebook output to stdout instead of files."
         )
 })
 
 
 class NbConvertApp(BaseIPythonApplication):
     """Application used to convert to and from notebook file type (*.ipynb)"""
 
     name = 'ipython-nbconvert'
     aliases = nbconvert_aliases
     flags = nbconvert_flags
     
     def _classes_default(self):
         classes = [NbConvertBase]
         for pkg in (exporters, transformers, writers):
             for name in dir(pkg):
                 cls = getattr(pkg, name)
                 if isinstance(cls, type) and issubclass(cls, Configurable):
                     classes.append(cls)
         return classes
 
     description = Unicode(
         u"""This application is used to convert notebook files (*.ipynb)
         to various other formats.""")
 
     examples = Unicode(u"""
         The simplest way to use nbconvert is
         
         > ipython nbconvert mynotebook.ipynb
         
         which will convert mynotebook.ipynb to the default format (probably HTML).
         
         You can specify the export format with `--format`.
         Options include {0}
         
         > ipython nbconvert --format latex mynotebook.ipnynb
         
         You can also pipe the output to stdout, rather than a file
         
         > ipython nbconvert mynotebook.ipynb --stdout
         
         Multiple notebooks can be given at the command line in a couple of 
         different ways:
   
         > ipython nbconvert notebook*.ipynb
         > ipython nbconvert notebook1.ipynb notebook2.ipynb
         
         or you can specify the notebooks list in a config file, containing::
         
             c.NbConvertApp.notebooks = ["my_notebook.ipynb"]
         
         > ipython nbconvert --config mycfg.py
         """.format(get_export_names()))
     # Writer specific variables
     writer = Instance('IPython.nbconvert.writers.base.WriterBase',  
                       help="""Instance of the writer class used to write the 
                       results of the conversion.""")
     writer_class = DottedObjectName('FilesWriter', config=True, 
                                     help="""Writer class used to write the 
                                     results of the conversion""")
     writer_aliases = {'FilesWriter': 'IPython.nbconvert.writers.files.FilesWriter',
                       'DebugWriter': 'IPython.nbconvert.writers.debug.DebugWriter',
                       'StdoutWriter': 'IPython.nbconvert.writers.stdout.StdoutWriter'}
     writer_factory = Type()
 
     def _writer_class_changed(self, name, old, new):
         if new in self.writer_aliases:
             new = self.writer_aliases[new]
         self.writer_factory = import_item(new)
 
 
     # Other configurable variables
     export_format = CaselessStrEnum(get_export_names(),
         default_value="full_html",
         config=True,
         help="""The export format to be used."""
     )
 
     notebooks = List([], config=True, help="""List of notebooks to convert.
                      Wildcards are supported.
                      Filenames passed positionally will be added to the list.
                      """)
 
     @catch_config_error
     def initialize(self, argv=None):
         super(NbConvertApp, self).initialize(argv)
         self.init_notebooks()
         self.init_writer()
 
     def init_notebooks(self):
         """Construct the list of notebooks.
         If notebooks are passed on the command-line,
         they override notebooks specified in config files.
         Glob each notebook to replace notebook patterns with filenames.
         """
 
         # Specifying notebooks on the command-line overrides (rather than adds)
         # the notebook list
         if self.extra_args:
             patterns = self.extra_args
         else:
             patterns = self.notebooks
 
         # Use glob to replace all the notebook patterns with filenames.
         filenames = []
         for pattern in patterns:
             
             # Use glob to find matching filenames.  Allow the user to convert 
             # notebooks without having to type the extension.
             globbed_files = glob.glob(pattern)
             globbed_files.extend(glob.glob(pattern + '.ipynb'))
 
             for filename in globbed_files:
                 if not filename in filenames:
                     filenames.append(filename)
         self.notebooks = filenames
 
     def init_writer(self):
         """
         Initialize the writer (which is stateless)
         """
         self._writer_class_changed(None, self.writer_class, self.writer_class)
         self.writer = self.writer_factory(parent=self)
 
     def start(self):
         """
         Ran after initialization completed
         """
         super(NbConvertApp, self).start()
         self.convert_notebooks()
 
     def convert_notebooks(self):
         """
         Convert the notebooks in the self.notebook traitlet
         """
         # Export each notebook
         conversion_success = 0
         for notebook_filename in self.notebooks:
 
             # Get a unique key for the notebook and set it in the resources object.
             basename = os.path.basename(notebook_filename)
             notebook_name = basename[:basename.rfind('.')]
             resources = {}
             resources['unique_key'] = notebook_name
             resources['output_files_dir'] = '%s_files' % notebook_name
 
             # Try to export
             try:
                 output, resources = export_by_name(self.export_format,
                                               notebook_filename, 
                                               resources=resources,
                                               config=self.config)
             except ExporterNameError as e:
-                print("Error: '%s' exporter not found." % self.export_format,
+                print("Error while converting '%s': '%s' exporter not found."
+                      %(notebook_filename, self.export_format),
                       file=sys.stderr)
                 print("Known exporters are:",
                       "\n\t" + "\n\t".join(get_export_names()),
                       file=sys.stderr)
                 sys.exit(-1)
+            except ConversionException as e:
+                print("Error while converting '%s': %s" %(notebook_filename, e),
+                      file=sys.stderr)
+                sys.exit(-1)
+            # except Exception as e:
+                # print("Error: could not export '%s'" % notebook_filename, file=sys.stderr)
+                # print(e, file=sys.stderr)
             else:
                 self.writer.write(output, resources, notebook_name=notebook_name)
                 conversion_success += 1
 
         # If nothing was converted successfully, help the user.
         if conversion_success == 0:
             self.print_help()
             sys.exit(-1)
 
 
 #-----------------------------------------------------------------------------
 # Main entry point
 #-----------------------------------------------------------------------------
 
 launch_new_instance = NbConvertApp.launch_instance

IPython/nbconvert/utils/exceptions.py

@@ -1,17 +1,17 b''
 """NbConvert specific exceptions"""
 #-----------------------------------------------------------------------------
 # 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.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 class ConversionException(Exception):
     """An exception raised by the conversion process."""
 
-    pass
  No newline at end of file
+    pass

IPython/nbconvert/utils/pandoc.py

@@ -1,71 +1,69 b''
 """Utility for calling pandoc"""
 #-----------------------------------------------------------------------------
 # 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
 #-----------------------------------------------------------------------------
 
 from __future__ import print_function
 
 # Stdlib imports
 import subprocess
 
 # IPython imports
 from IPython.utils.py3compat import cast_bytes
 
+from .exceptions import ConversionException
+
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
-class PandocMissing(SystemExit):
-    """Exception raised when Pandoc is missing.
-
-    A subclass of SystemExit so it will cause an exit if not caught, but
-    explicitly named so that it's possible to catch.
-    """
+class PandocMissing(ConversionException):
+    """Exception raised when Pandoc is missing. """
     pass
 
 
 def pandoc(source, fmt, to, extra_args=None, encoding='utf-8'):
     """Convert an input string in format `from` to format `to` via pandoc.
 
     This function will raise an error if pandoc is not installed.
     Any error messages generated by pandoc are printed to stderr.
 
     Parameters
     ----------
     source : string
       Input string, assumed to be valid format `from`.
     fmt : string
       The name of the input format (markdown, etc.)
     to : string
       The name of the output format (html, etc.)
 
     Returns
     -------
     out : unicode
       Output as returned by pandoc.
     """
     command = ['pandoc', '-f', fmt, '-t', to]
     if extra_args:
         command.extend(extra_args)
     try:
         p = subprocess.Popen(command,
                              stdin=subprocess.PIPE, stdout=subprocess.PIPE
         )
     except OSError as e:
         raise PandocMissing(
-            "Error trying to run '%s': %s.\n" %(" ".join(command), e) +
+            "The command '%s' returned an error: %s.\n" %(" ".join(command), e) +
             "Please check that pandoc is installed:\n" +
             "http://johnmacfarlane.net/pandoc/installing.html"
         )
     out, _ = p.communicate(cast_bytes(source, encoding))
     out = out.decode(encoding, 'replace')
     return out[:-1]