use itertools.count for incrementing notebook filename

IPython/html/services/notebooks/filenbmanager.py

@@ -1,414 +1,409
 """A notebook manager that uses the local file system for storage.
 
 Authors:
 
 * Brian Granger
 * Zach Sailer
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
-import datetime
 import io
+import itertools
 import os
 import glob
 import shutil
 
-from unicodedata import normalize
-
 from tornado import web
 
 from .nbmanager import NotebookManager
 from IPython.nbformat import current
 from IPython.utils.traitlets import Unicode, Dict, Bool, TraitError
 from IPython.utils import tz
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class FileNotebookManager(NotebookManager):
     
     save_script = Bool(False, config=True,
         help="""Automatically create a Python script when saving the notebook.
         
         For easier use of import, %run and %load across notebooks, a
         <notebook-name>.py script will be created next to any
         <notebook-name>.ipynb on each save.  This can also be set with the
         short `--script` flag.
         """
     )
     
     checkpoint_dir = Unicode(config=True,
         help="""The location in which to keep notebook checkpoints
         
         By default, it is notebook-dir/.ipynb_checkpoints
         """
     )
     def _checkpoint_dir_default(self):
         return os.path.join(self.notebook_dir, '.ipynb_checkpoints')
     
     def _checkpoint_dir_changed(self, name, old, new):
         """do a bit of validation of the checkpoint dir"""
         if not os.path.isabs(new):
             # If we receive a non-absolute path, make it absolute.
             abs_new = os.path.abspath(new)
             self.checkpoint_dir = abs_new
             return
         if os.path.exists(new) and not os.path.isdir(new):
             raise TraitError("checkpoint dir %r is not a directory" % new)
         if not os.path.exists(new):
             self.log.info("Creating checkpoint dir %s", new)
             try:
                 os.mkdir(new)
             except:
                 raise TraitError("Couldn't create checkpoint dir %r" % new)
 
     def get_notebook_names(self, path=''):
         """List all notebook names in the notebook dir and path."""
         path = path.strip('/')
         if not os.path.isdir(self.get_os_path(path=path)):
             raise web.HTTPError(404, 'Directory not found: ' + path)
         names = glob.glob(self.get_os_path('*'+self.filename_ext, path))
         names = [os.path.basename(name)
                  for name in names]
         return names
 
-    def increment_filename(self, basename, path=''):
+    def increment_filename(self, basename, path='', ext='.ipynb'):
         """Return a non-used filename of the form basename<int>."""
         path = path.strip('/')
-        i = 0
-        while True:
-            name = u'%s%i.ipynb' % (basename,i)
+        for i in itertools.count():
+            name = u'{basename}{i}{ext}'.format(basename=basename, i=i, ext=ext)
             os_path = self.get_os_path(name, path)
             if not os.path.isfile(os_path):
                 break
-            else:
-                i = i+1
         return name
 
     def path_exists(self, path):
         """Does the API-style path (directory) actually exist?
         
         Parameters
         ----------
         path : string
             The path to check. This is an API path (`/` separated,
             relative to base notebook-dir).
         
         Returns
         -------
         exists : bool
             Whether the path is indeed a directory.
         """
         path = path.strip('/')
         os_path = self.get_os_path(path=path)
         return os.path.isdir(os_path)
     
     def get_os_path(self, name=None, path=''):
         """Given a notebook name and a URL path, return its file system
         path.
 
         Parameters
         ----------
         name : string
             The name of a notebook file with the .ipynb extension
         path : string
             The relative URL path (with '/' as separator) to the named
             notebook.
 
         Returns
         -------
         path : string
             A file system path that combines notebook_dir (location where
             server started), the relative path, and the filename with the
             current operating system's url.
         """
         parts = path.strip('/').split('/')
         parts = [p for p in parts if p != ''] # remove duplicate splits
         if name is not None:
             parts.append(name)
         path = os.path.join(self.notebook_dir, *parts)
         return path
 
     def notebook_exists(self, name, path=''):
         """Returns a True if the notebook exists. Else, returns False.
 
         Parameters
         ----------
         name : string
             The name of the notebook you are checking.
         path : string
             The relative path to the notebook (with '/' as separator)
 
         Returns
         -------
         bool
         """
         path = path.strip('/')
         nbpath = self.get_os_path(name, path=path)
         return os.path.isfile(nbpath)
 
     def list_notebooks(self, path):
         """Returns a list of dictionaries that are the standard model
         for all notebooks in the relative 'path'.
         
         Parameters
         ----------
         path : str
             the URL path that describes the relative path for the
             listed notebooks
         
         Returns
         -------
         notebooks : list of dicts
             a list of the notebook models without 'content'
         """
         path = path.strip('/')
         notebook_names = self.get_notebook_names(path)
         notebooks = []
         for name in notebook_names:
             model = self.get_notebook_model(name, path, content=False)
             notebooks.append(model)
         notebooks = sorted(notebooks, key=lambda item: item['name'])
         return notebooks
 
     def get_notebook_model(self, name, path='', content=True):
         """ Takes a path and name for a notebook and returns it's model
         
         Parameters
         ----------
         name : str
             the name of the notebook
         path : str
             the URL path that describes the relative path for
             the notebook
             
         Returns
         -------
         model : dict
             the notebook model. If contents=True, returns the 'contents' 
             dict in the model as well.
         """
         path = path.strip('/')
         if not self.notebook_exists(name=name, path=path):
             raise web.HTTPError(404, u'Notebook does not exist: %s' % name)
         os_path = self.get_os_path(name, path)
         info = os.stat(os_path)
         last_modified = tz.utcfromtimestamp(info.st_mtime)
         created = tz.utcfromtimestamp(info.st_ctime)
         # Create the notebook model.
         model ={}
         model['name'] = name
         model['path'] = path
         model['last_modified'] = last_modified
         model['created'] = created
         if content is True:
             with io.open(os_path, 'r', encoding='utf-8') as f:
                 try:
                     nb = current.read(f, u'json')
                 except Exception as e:
                     raise web.HTTPError(400, u"Unreadable Notebook: %s %s" % (os_path, e))
             model['content'] = nb
         return model
 
     def save_notebook_model(self, model, name='', path=''):
         """Save the notebook model and return the model with no content."""
         path = path.strip('/')
 
         if 'content' not in model:
             raise web.HTTPError(400, u'No notebook JSON data provided')
 
         new_path = model.get('path', path).strip('/')
         new_name = model.get('name', name)
 
         if path != new_path or name != new_name:
             self.rename_notebook(name, path, new_name, new_path)
 
         # Save the notebook file
         os_path = self.get_os_path(new_name, new_path)
         nb = current.to_notebook_json(model['content'])
         if 'name' in nb['metadata']:
             nb['metadata']['name'] = u''
         try:
             self.log.debug("Autosaving notebook %s", os_path)
             with io.open(os_path, 'w', encoding='utf-8') as f:
                 current.write(nb, f, u'json')
         except Exception as e:
             raise web.HTTPError(400, u'Unexpected error while autosaving notebook: %s %s' % (os_path, e))
 
         # Save .py script as well
         if self.save_script:
             py_path = os.path.splitext(os_path)[0] + '.py'
             self.log.debug("Writing script %s", py_path)
             try:
                 with io.open(py_path, 'w', encoding='utf-8') as f:
                     current.write(model, f, u'py')
             except Exception as e:
                 raise web.HTTPError(400, u'Unexpected error while saving notebook as script: %s %s' % (py_path, e))
 
         model = self.get_notebook_model(new_name, new_path, content=False)
         return model
 
     def update_notebook_model(self, model, name, path=''):
         """Update the notebook's path and/or name"""
         path = path.strip('/')
         new_name = model.get('name', name)
         new_path = model.get('path', path).strip('/')
         if path != new_path or name != new_name:
             self.rename_notebook(name, path, new_name, new_path)
         model = self.get_notebook_model(new_name, new_path, content=False)
         return model
 
     def delete_notebook_model(self, name, path=''):
         """Delete notebook by name and path."""
         path = path.strip('/')
         os_path = self.get_os_path(name, path)
         if not os.path.isfile(os_path):
             raise web.HTTPError(404, u'Notebook does not exist: %s' % os_path)
         
         # clear checkpoints
         for checkpoint in self.list_checkpoints(name, path):
             checkpoint_id = checkpoint['id']
             cp_path = self.get_checkpoint_path(checkpoint_id, name, path)
             if os.path.isfile(cp_path):
                 self.log.debug("Unlinking checkpoint %s", cp_path)
                 os.unlink(cp_path)
         
         self.log.debug("Unlinking notebook %s", os_path)
         os.unlink(os_path)
 
     def rename_notebook(self, old_name, old_path, new_name, new_path):
         """Rename a notebook."""
         old_path = old_path.strip('/')
         new_path = new_path.strip('/')
         if new_name == old_name and new_path == old_path:
             return
         
         new_os_path = self.get_os_path(new_name, new_path)
         old_os_path = self.get_os_path(old_name, old_path)
 
         # Should we proceed with the move?
         if os.path.isfile(new_os_path):
             raise web.HTTPError(409, u'Notebook with name already exists: %s' % new_os_path)
         if self.save_script:
             old_py_path = os.path.splitext(old_os_path)[0] + '.py'
             new_py_path = os.path.splitext(new_os_path)[0] + '.py'
             if os.path.isfile(new_py_path):
                 raise web.HTTPError(409, u'Python script with name already exists: %s' % new_py_path)
 
         # Move the notebook file
         try:
             os.rename(old_os_path, new_os_path)
         except Exception as e:
             raise web.HTTPError(500, u'Unknown error renaming notebook: %s %s' % (old_os_path, e))
 
         # Move the checkpoints
         old_checkpoints = self.list_checkpoints(old_name, old_path)
         for cp in old_checkpoints:
             checkpoint_id = cp['id']
             old_cp_path = self.get_checkpoint_path(checkpoint_id, old_name, old_path)
             new_cp_path = self.get_checkpoint_path(checkpoint_id, new_name, new_path)
             if os.path.isfile(old_cp_path):
                 self.log.debug("Renaming checkpoint %s -> %s", old_cp_path, new_cp_path)
                 os.rename(old_cp_path, new_cp_path)
 
         # Move the .py script
         if self.save_script:
             os.rename(old_py_path, new_py_path)
   
     # Checkpoint-related utilities
     
     def get_checkpoint_path(self, checkpoint_id, name, path=''):
         """find the path to a checkpoint"""
         path = path.strip('/')
         filename = u"{name}-{checkpoint_id}{ext}".format(
             name=name,
             checkpoint_id=checkpoint_id,
             ext=self.filename_ext,
         )
         cp_path = os.path.join(path, self.checkpoint_dir, filename)
         return cp_path
 
     def get_checkpoint_model(self, checkpoint_id, name, path=''):
         """construct the info dict for a given checkpoint"""
         path = path.strip('/')
         cp_path = self.get_checkpoint_path(checkpoint_id, name, path)
         stats = os.stat(cp_path)
         last_modified = tz.utcfromtimestamp(stats.st_mtime)
         info = dict(
             id = checkpoint_id,
             last_modified = last_modified,
         )
         return info
         
     # public checkpoint API
     
     def create_checkpoint(self, name, path=''):
         """Create a checkpoint from the current state of a notebook"""
         path = path.strip('/')
         nb_path = self.get_os_path(name, path)
         # only the one checkpoint ID:
         checkpoint_id = u"checkpoint"
         cp_path = self.get_checkpoint_path(checkpoint_id, name, path)
         self.log.debug("creating checkpoint for notebook %s", name)
         if not os.path.exists(self.checkpoint_dir):
             os.mkdir(self.checkpoint_dir)
         shutil.copy2(nb_path, cp_path)
         
         # return the checkpoint info
         return self.get_checkpoint_model(checkpoint_id, name, path)
     
     def list_checkpoints(self, name, path=''):
         """list the checkpoints for a given notebook
         
         This notebook manager currently only supports one checkpoint per notebook.
         """
         path = path.strip('/')
         checkpoint_id = "checkpoint"
         path = self.get_checkpoint_path(checkpoint_id, name, path)
         if not os.path.exists(path):
             return []
         else:
             return [self.get_checkpoint_model(checkpoint_id, name, path)]
         
     
     def restore_checkpoint(self, checkpoint_id, name, path=''):
         """restore a notebook to a checkpointed state"""
         path = path.strip('/')
         self.log.info("restoring Notebook %s from checkpoint %s", name, checkpoint_id)
         nb_path = self.get_os_path(name, path)
         cp_path = self.get_checkpoint_path(checkpoint_id, name, path)
         if not os.path.isfile(cp_path):
             self.log.debug("checkpoint file does not exist: %s", cp_path)
             raise web.HTTPError(404,
                 u'Notebook checkpoint does not exist: %s-%s' % (name, checkpoint_id)
             )
         # ensure notebook is readable (never restore from an unreadable notebook)
         with io.open(cp_path, 'r', encoding='utf-8') as f:
             nb = current.read(f, u'json')
         shutil.copy2(cp_path, nb_path)
         self.log.debug("copying %s -> %s", cp_path, nb_path)
     
     def delete_checkpoint(self, checkpoint_id, name, path=''):
         """delete a notebook's checkpoint"""
         path = path.strip('/')
         cp_path = self.get_checkpoint_path(checkpoint_id, name, path)
         if not os.path.isfile(cp_path):
             raise web.HTTPError(404,
                 u'Notebook checkpoint does not exist: %s%s-%s' % (path, name, checkpoint_id)
             )
         self.log.debug("unlinking %s", cp_path)
         os.unlink(cp_path)
     
     def info_string(self):
         return "Serving notebooks from local directory: %s" % self.notebook_dir