print supported TARGETs for nbconvert --help

IPython/nbconvert/nbconvertapp.py

@@ -1,226 +1,234 b''
 #!/usr/bin/env python
 """NBConvert is a utility for conversion of IPYNB files.
 
 Commandline interface for the NBConvert conversion utility.  Read the
 readme.rst for usage information
 """
 #-----------------------------------------------------------------------------
 #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 io
 import os
 
 #From IPython
 from IPython.config.application import Application
 from IPython.utils.traitlets import Bool, Unicode
 
 from .exporters.export import export_by_name, get_export_names
 from .exporters.exporter import Exporter
 from .transformers import extractfigure
 from .utils.config import GlobalConfigurable
 
 #-----------------------------------------------------------------------------
 #Globals and constants
 #-----------------------------------------------------------------------------
 
 #'Keys in resources' user prompt.
 KEYS_PROMPT_HEAD = "====================== Keys in Resources =================================="
 KEYS_PROMPT_BODY = """
 ===========================================================================
 You are responsible for writing these files into the appropriate
 directory(ies) if need be.  If you do not want to see this message, enable
 the 'write' (boolean) flag of the converter.
 ===========================================================================
 """
 
 _examples = """
 ipython nbconvert rst Untitled0.ipynb    # convert ipynb to ReStructured Text
 ipython nbconvert latex Untitled0.ipynb  # convert ipynb to LaTeX
 ipython nbconvert reveal Untitled0.ipynb # convert to Reveal (HTML/JS) slideshow
 """
 
+
 #-----------------------------------------------------------------------------
 #Classes and functions
 #-----------------------------------------------------------------------------
 
 class NbConvertApp(Application):
-    """Application used to convert to and from notebook file type (*.ipynb)"""
+    __doc__ = """IPython notebook conversion utility
+    
+Convert to and from notebook file type (*.ipynb)
+
+    ipython nbconvert TARGET FILENAME
+
+Supported export TARGETs are: %s
+""" % (" ".join(get_export_names()))
     description = Unicode(__doc__)
 
     examples = _examples
 
     stdout = Bool(
         False, config=True,
         help="""Whether to print the converted IPYNB file to stdout
         use full do diff files without actually writing a new file"""
         )
 
     write = Bool(
         True, config=True,
         help="""Should the converted notebook file be written to disk
         along with potential extracted resources."""
         )
 
     aliases = {
              'stdout':'NbConvertApp.stdout',
              'write':'NbConvertApp.write',
              }
 
     flags = {}
 
     flags['stdout'] = (
         {'NbConvertApp' : {'stdout' : True}},
     """Print converted file to stdout, equivalent to --stdout=True
     """
     )
 
     flags['no-write'] = (
         {'NbConvertApp' : {'write' : True}},
     """Do not write to disk, equivalent to --write=False
     """
     )
 
 
     def __init__(self, **kwargs):
         """Public constructor"""
 
         #Call base class
         super(NbConvertApp, self).__init__(**kwargs)
 
         #Register class here to have help with help all
         self.classes.insert(0, Exporter)
         self.classes.insert(0, GlobalConfigurable)
 
 
     def start(self, argv=None):
         """Entrypoint of NbConvert application.
         
         Parameters
         ----------
         argv : list
             Commandline arguments
         """
         
         #Parse the commandline options.
         self.parse_command_line(argv)
 
         #Call base
         super(NbConvertApp, self).start()
 
         #The last arguments in list will be used by nbconvert
         if len(self.extra_args) is not 3:
             print( "Wrong number of arguments, use --help flag for usage", file=sys.stderr)
             sys.exit(-1)
         export_type = (self.extra_args)[1]
         ipynb_file = (self.extra_args)[2]
         
         #Export
         try:
             return_value = export_by_name(export_type, ipynb_file)
         except NameError as e:
             print("Error: '%s' exporter not found." % export_type,
                   file=sys.stderr)
             print("Known exporters are:",
                   "\n\t" + "\n\t".join(get_export_names()),
                   file=sys.stderr)
             sys.exit(-1)
         else:
             (output, resources, exporter) = return_value 
         
         #TODO: Allow user to set output directory and file. 
         destination_filename = None
         destination_directory = None
         if self.write:
                 
             #Get the file name without the '.ipynb' (6 chars) extension and then
             #remove any addition periods and spaces. The resulting name will
             #be used to create the directory that the files will be exported
             #into.
             out_root = ipynb_file[:-6].replace('.', '_').replace(' ', '_')
             destination_filename = os.path.join(out_root+'.'+exporter.file_extension)
             
             destination_directory = out_root+'_files'
             if not os.path.exists(destination_directory):
                 os.mkdir(destination_directory)
                 
         #Write the results
         if self.stdout or not (destination_filename is None and destination_directory is None):
             self._write_results(output, resources, destination_filename, destination_directory)
 
 
     def _write_results(self, output, resources, destination_filename=None, destination_directory=None):
         """Output the conversion results to the console and/or filesystem
         
         Parameters
         ----------
         output : str
             Output of conversion
         resources : dictionary
             Additional input/output used by the transformers.  For
             example, the ExtractFigure transformer outputs the
             figures it extracts into this dictionary.  This method
             relies on the figures being in this dictionary when
             attempting to write the figures to the file system.
         destination_filename : str, Optional
             Filename to write output into.  If None, output is not 
             written to a file.
         destination_directory : str, Optional 
             Directory to write notebook data (i.e. figures) to.  If
             None, figures are not written to the file system.
         """
         
         if self.stdout:
             print(output.encode('utf-8'))
 
         #Write file output from conversion.
         if not destination_filename is None:
             with io.open(destination_filename, 'w') as f:
                 f.write(output)
 
         #Get the key names used by the extract figure transformer
         figures_key = extractfigure.FIGURES_KEY
         binary_key = extractfigure.BINARY_KEY
         text_key = extractfigure.TEXT_KEY
         
         #Output any associate figures into the same "root" directory.
         binkeys = resources.get(figures_key, {}).get(binary_key,{}).keys()
         textkeys = resources.get(figures_key, {}).get(text_key,{}).keys()
         if binkeys or textkeys :
             if not destination_directory is None:
                 for key in binkeys:
                     with io.open(os.path.join(destination_directory, key), 'wb') as f:
                         f.write(resources[figures_key][binary_key][key])
                 for key in textkeys:
                     with io.open(os.path.join(destination_directory, key), 'w') as f:
                         f.write(resources[figures_key][text_key][key])
 
             #Figures that weren't exported which will need to be created by the
             #user.  Tell the user what figures these are.
             if self.stdout:
                 print(KEYS_PROMPT_HEAD, file=sys.stderr)
                 print(resources[figures_key].keys(), file=sys.stderr)
                 print(KEYS_PROMPT_BODY , file=sys.stderr)
 
 #-----------------------------------------------------------------------------
 # Main entry point
 #-----------------------------------------------------------------------------
 
 def launch_new_instance():
     """Application entry point"""
 
     app = NbConvertApp.instance()
     app.description = __doc__
     app.start(argv=sys.argv)