title: Nbconvertapp doesn't exist
body: <p>I'm on Ubuntu, I'm using Python 2.7.6 and Ipython 4.0.3. I'm trying to convert a ipynb file to a pdf file. It gives the following error:</p>
  
  <pre><code>ipython nbconvert --to pdf mine.ipynb 
  Traceback (most recent call last):
  File "/usr/bin/ipython", line 6, in &lt;module&gt;
  start_ipython()
  File "/usr/local/lib/python2.7/dist-packages/IPython/__init__.py", line    119, in start_ipython
  return launch_new_instance(argv=argv, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/traitlets/config    /application.py", line 588, in launch_instance
  app.initialize(argv)
  File "&lt;decorator-gen-111&gt;", line 2, in initialize
  File "/usr/local/lib/python2.7/dist-packages/traitlets/config/application.py", line 74, in catch_config_error
  return method(app, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/IPython/terminal/ipapp.py", line 305, in initialize
  super(TerminalIPythonApp, self).initialize(argv)
  File "&lt;decorator-gen-7&gt;", line 2, in initialize
  File "/usr/local/lib/python2.7/dist-packages/traitlets/config/application.py", line 74, in catch_config_error
  return method(app, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/IPython/core/application.py", line 386, in initialize
  self.parse_command_line(argv)
  File "/usr/local/lib/python2.7/dist-packages/IPython/terminal/ipapp.py", line 300, in parse_command_line
  return super(TerminalIPythonApp, self).parse_command_line(argv)
  File "&lt;decorator-gen-4&gt;", line 2, in parse_command_line
  File "/usr/local/lib/python2.7/dist-packages/traitlets/config/application.py", line 74, in catch_config_error
  return method(app, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/traitlets/config/application.py", line 485, in parse_command_line
  return self.initialize_subcommand(subc, subargv)
  File "&lt;decorator-gen-3&gt;", line 2, in initialize_subcommand
  File "/usr/local/lib/python2.7/dist-packages/traitlets/config/application.py", line 74, in catch_config_error
  return method(app, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/traitlets/config/application.py", line 416, in initialize_subcommand
  subapp = import_item(subapp)
  File "/usr/local/lib/python2.7/dist-packages/ipython_genutils/importstring.py", line 31, in import_item
  module = __import__(package, fromlist=[obj])
  ImportError: No module named nbconvert.nbconvertapp
  </code></pre>
  
  <p>I googled the last line and found nothing. Any idea is appreciated. Thanks.</p>