removing spurious import

IPython/html/nbconvert/handlers.py

@@ -1,162 +1,161 b''
 """Tornado handlers for nbconvert."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import io
 import os
 import zipfile
-import collections
 
 from tornado import web
 
 from ..base.handlers import (
     IPythonHandler, FilesRedirectHandler,
     path_regex,
 )
 from IPython.nbformat import from_dict
 
 from IPython.utils.py3compat import cast_bytes
 from IPython.utils import text
 
 def find_resource_files(output_files_dir):
     files = []
     for dirpath, dirnames, filenames in os.walk(output_files_dir):
         files.extend([os.path.join(dirpath, f) for f in filenames])
     return files
 
 def respond_zip(handler, name, output, resources):
     """Zip up the output and resource files and respond with the zip file.
 
     Returns True if it has served a zip file, False if there are no resource
     files, in which case we serve the plain output file.
     """
     # Check if we have resource files we need to zip
     output_files = resources.get('outputs', None)
     if not output_files:
         return False
 
     # Headers
     zip_filename = os.path.splitext(name)[0] + '.zip'
     handler.set_header('Content-Disposition',
                        'attachment; filename="%s"' % zip_filename)
     handler.set_header('Content-Type', 'application/zip')
 
     # Prepare the zip file
     buffer = io.BytesIO()
     zipf = zipfile.ZipFile(buffer, mode='w', compression=zipfile.ZIP_DEFLATED)
     output_filename = os.path.splitext(name)[0] + resources['output_extension']
     zipf.writestr(output_filename, cast_bytes(output, 'utf-8'))
     for filename, data in output_files.items():
         zipf.writestr(os.path.basename(filename), data)
     zipf.close()
 
     handler.finish(buffer.getvalue())
     return True
 
 def get_exporter(format, **kwargs):
     """get an exporter, raising appropriate errors"""
     # if this fails, will raise 500
     try:
         from IPython.nbconvert.exporters.export import exporter_map
     except ImportError as e:
         raise web.HTTPError(500, "Could not import nbconvert: %s" % e)
     
     try:
         Exporter = exporter_map[format]
     except KeyError:
         # should this be 400?
         raise web.HTTPError(404, u"No exporter for format: %s" % format)
     
     try:
         return Exporter(**kwargs)
     except Exception as e:
         raise web.HTTPError(500, "Could not construct Exporter: %s" % e)
 
 class NbconvertFileHandler(IPythonHandler):
 
     SUPPORTED_METHODS = ('GET',)
     
     @web.authenticated
     def get(self, format, path):
         
         exporter = get_exporter(format, config=self.config, log=self.log)
         
         path = path.strip('/')
         model = self.contents_manager.get(path=path)
         name = model['name']
         if model['type'] != 'notebook':
             raise web.HTTPError(400, "Not a notebook: %s" % path)
 
         self.set_header('Last-Modified', model['last_modified'])
 
         try:
             output, resources = exporter.from_notebook_node(
                 model['content'],
                 resources={
                     "metadata": {
                         "name": name[:name.rfind('.')],
                         "modified_date": (model['last_modified']
                             .strftime(text.date_format))
                     }
                 }
             )
         except Exception as e:
             raise web.HTTPError(500, "nbconvert failed: %s" % e)
 
         if respond_zip(self, name, output, resources):
             return
 
         # Force download if requested
         if self.get_argument('download', 'false').lower() == 'true':
             filename = os.path.splitext(name)[0] + resources['output_extension']
             self.set_header('Content-Disposition',
                                'attachment; filename="%s"' % filename)
 
         # MIME type
         if exporter.output_mimetype:
             self.set_header('Content-Type',
                             '%s; charset=utf-8' % exporter.output_mimetype)
 
         self.finish(output)
 
 class NbconvertPostHandler(IPythonHandler):
     SUPPORTED_METHODS = ('POST',)
 
     @web.authenticated
     def post(self, format):
         exporter = get_exporter(format, config=self.config)
         
         model = self.get_json_body()
         name = model.get('name', 'notebook.ipynb')
         nbnode = from_dict(model['content'])
         
         try:
             output, resources = exporter.from_notebook_node(nbnode)
         except Exception as e:
             raise web.HTTPError(500, "nbconvert failed: %s" % e)
 
         if respond_zip(self, name, output, resources):
             return
 
         # MIME type
         if exporter.output_mimetype:
             self.set_header('Content-Type',
                             '%s; charset=utf-8' % exporter.output_mimetype)
 
         self.finish(output)
 
 
 #-----------------------------------------------------------------------------
 # URL to handler mappings
 #-----------------------------------------------------------------------------
 
 _format_regex = r"(?P<format>\w+)"
 
 
 default_handlers = [
     (r"/nbconvert/%s" % _format_regex, NbconvertPostHandler),
     (r"/nbconvert/%s%s" % (_format_regex, path_regex),
          NbconvertFileHandler),
     (r"/nbconvert/html%s" % path_regex, FilesRedirectHandler),
 ]