Added a --clean notebook option to save .clean files w/o output.

- This exactly mimics the behaviour of the --script option and
  should probably be removed once a method for hooking into the
  save command is established.

Author: mforbes

IPython/html/notebookapp.py

@@ -236,10 +236,15 @@ def init_handlers(self, settings):
                'Auto-save a .py script everytime the .ipynb notebook is saved',
                'Do not auto-save .py scripts for every notebook'))
 
+flags.update(boolean_flag('clean', 'FileNotebookManager.save_clean',
+              'Save a ".clean" (no output) version when the notebook is saved.',
+              'Do auto-save a ".clean" (no output) version'))
+
 # the flags that are specific to the frontend
 # these must be scrubbed before being passed to the kernel,
 # or it will raise an error on unrecognized flags
-notebook_flags = ['no-browser', 'no-mathjax', 'script', 'no-script']
+notebook_flags = ['no-browser', 'no-mathjax', 'script', 'no-script', 
+                  'clean', 'no-clean']
 
 aliases = dict(kernel_aliases)
 

IPython/html/services/notebooks/filenbmanager.py

@@ -30,6 +30,19 @@
 from IPython.utils.traitlets import Unicode, Dict, Bool, TraitError
 from IPython.utils import tz
 
+def clean_nb(nb):
+    """Return a clean copy of the notebook nb with all output removed."""
+    clean_nb = nb.copy()
+
+    # Strip out all of the output and prompt_number sections
+    for worksheet in clean_nb["worksheets"]:
+        for cell in worksheet["cells"]:
+            if "outputs" in cell:
+                del cell.outputs[:]
+            if "prompt_number" in cell:
+                del cell["prompt_number"]
+    return clean_nb
+
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
@@ -46,6 +59,13 @@ class FileNotebookManager(NotebookManager):
         """
     )
 
+    save_clean = Bool(False, config=True,
+        help="""Save a clean (output removed) version when saving the notebook.
+        
+        This can also be set with the short `--clean` flag.
+        """
+    )
+
     checkpoint_dir = Unicode(config=True,
         help="""The location in which to keep notebook checkpoints
         
@@ -255,6 +275,16 @@ def save_notebook_model(self, model, name='', path=''):
             except Exception as e:
                 raise web.HTTPError(400, u'Unexpected error while saving notebook as script: %s %s' % (py_path, e))
 
+        # Save .ipynb.clean as well.
+        if self.save_clean:
+            py_path = os_path + '.clean'
+            self.log.debug("Writing clean file %s", py_path)
+            try:
+                with io.open(py_path, 'w', encoding='utf-8') as f:
+                    current.write(clean_nb(nb), f, u'ipynb')
+            except Exception as e:
+                raise web.HTTPError(400, u'Unexpected error while saving clean notebook: %s %s' % (py_path, e))
+
         model = self.get_notebook_model(new_name, new_path, content=False)
         return model
 
@@ -305,6 +335,12 @@ def rename_notebook(self, old_name, old_path, new_name, new_path):
             if os.path.isfile(new_py_path):
                 raise web.HTTPError(409, u'Python script with name already exists: %s' % new_py_path)
 
+        if self.save_clean:
+            old_clean_path = old_os_path + '.clean'
+            new_clean_path = new_os_path + '.clean'
+            if os.path.isfile(new_py_path):
+                raise web.HTTPError(409, u'Clean notebook with name already exists: %s' % new_py_path)
+
         # Move the notebook file
         try:
             os.rename(old_os_path, new_os_path)
@@ -324,6 +360,10 @@ def rename_notebook(self, old_name, old_path, new_name, new_path):
         # Move the .py script
         if self.save_script:
             os.rename(old_py_path, new_py_path)
+
+        # Move the .clean file
+        if self.save_clean:
+            os.rename(old_clean_path, new_clean_path)
 
     # Checkpoint-related utilities
 

IPython/html/services/notebooks/tests/test_nbmanager.py

@@ -215,6 +215,25 @@ def test_save_notebook_with_script(self):
             py_path = os.path.join(td, os.path.splitext(name)[0]+'.py')
             assert os.path.exists(py_path), py_path
 
+    def test_save_notebook_with_clean(self):
+        with TemporaryDirectory() as td:
+            # Create a notebook
+            nm = FileNotebookManager(notebook_dir=td)
+            nm.save_clean = True
+            model = nm.create_notebook_model()
+            name = model['name']
+            path = model['path']
+
+            # Get the model with 'content'
+            full_model = nm.get_notebook_model(name, path)
+
+            # Save the notebook
+            model = nm.save_notebook_model(full_model, name, path)
+
+            # Check that the script was created
+            py_path = os.path.join(td, name+'.clean')
+            assert os.path.exists(py_path), py_path
+
     def test_delete_notebook_model(self):
         with TemporaryDirectory() as td:
             # Test in the root directory