Improvements to file uploaded, mime types and .py reader.

* The .py notebook reader now uses that ast module to split
  a plain python file into blocks. These blocks become cells in
  the notebook.
* Proper mime types are used for xml (application/xml), json
  (application/json) and python (application/x-python).
* Other fixes to file uploading.

IPython/frontend/html/notebook/handlers.py

@@ -41,12 +41,12 b' class NamedNotebookHandler(web.RequestHandler):'
 class KernelHandler(web.RequestHandler):
 
     def get(self):
-        self.write(json.dumps(self.application.kernel_ids))
+        self.finish(json.dumps(self.application.kernel_ids))
 
     def post(self):
         kernel_id = self.application.start_kernel()
         self.set_header('Location', '/'+kernel_id)
-        self.write(json.dumps(kernel_id))
+        self.finish(json.dumps(kernel_id))
 
 
 class KernelActionHandler(web.RequestHandler):
@@ -58,6 +58,7 b' class KernelActionHandler(web.RequestHandler):'
         if action == 'restart':
             new_kernel_id = self.application.restart_kernel(kernel_id)
             self.write(json.dumps(new_kernel_id))
+        self.finish()
 
 
 class ZMQStreamHandler(websocket.WebSocketHandler):
@@ -83,7 +84,7 b' class NotebookRootHandler(web.RequestHandler):'
     def get(self):
         nbm = self.application.notebook_manager
         files = nbm.list_notebooks()
-        self.write(json.dumps(files))
+        self.finish(json.dumps(files))
 
     def post(self):
         nbm = self.application.notebook_manager
@@ -95,7 +96,7 b' class NotebookRootHandler(web.RequestHandler):'
         else:
             notebook_id = nbm.new_notebook()
         self.set_header('Location', '/'+notebook_id)
-        self.write(json.dumps(notebook_id))
+        self.finish(json.dumps(notebook_id))
 
 
 class NotebookHandler(web.RequestHandler):
@@ -110,10 +111,10 b' class NotebookHandler(web.RequestHandler):'
             self.set_header('Content-Type', 'application/json')
             self.set_header('Content-Disposition','attachment; filename=%s.json' % name)
         elif format == u'xml':
-            self.set_header('Content-Type', 'text/xml')
+            self.set_header('Content-Type', 'application/xml')
             self.set_header('Content-Disposition','attachment; filename=%s.ipynb' % name)
         elif format == u'py':
-            self.set_header('Content-Type', 'text/plain')
+            self.set_header('Content-Type', 'application/x-python')
             self.set_header('Content-Disposition','attachment; filename=%s.py' % name)
         self.set_header('Last-Modified', last_mod)
         self.finish(data)

IPython/frontend/html/notebook/static/js/notebook.js

@@ -559,11 +559,12 b' var IPython = (function (IPython) {'
             data.id = notebook_id
             // We do the call with settings so we can set cache to false.
             var settings = {
-              processData : false,
-              cache : false,
-              type : "PUT",
-              data : JSON.stringify(data),
-              success : $.proxy(this.notebook_saved,this)
+                processData : false,
+                cache : false,
+                type : "PUT",
+                data : JSON.stringify(data),
+                headers : {'Content-Type': 'application/json'},
+                success : $.proxy(this.notebook_saved,this)
             };
             IPython.save_widget.status_saving();
             $.ajax("/notebooks/" + notebook_id, settings);

IPython/frontend/html/notebook/static/js/notebooklist.js

@@ -191,12 +191,21 b' var IPython = (function (IPython) {'
                 var nbname = item.find('.item_name > input').attr('value');
                 var nbformat = item.data('nbformat');
                 var nbdata = item.data('nbdata');
+                var content_type = 'text/plain';
+                if (nbformat === 'xml') {
+                    content_type = 'application/xml';
+                } else if (nbformat === 'json') {
+                    content_type = 'application/json';
+                } else if (nbformat === 'py') {
+                    content_type = 'application/x-python';
+                };
                 var settings = {
                     processData : false,
                     cache : false,
-                    type : "POST",
-                    dataType : "json",
+                    type : 'POST',
+                    dataType : 'json',
                     data : nbdata,
+                    headers : {'Content-Type': content_type},
                     success : function (data, status, xhr) {
                         that.add_link(data, nbname, item);
                         that.add_delete_button(item);
@@ -204,7 +213,7 b' var IPython = (function (IPython) {'
                 };
 
                 var qs = $.param({name:nbname, format:nbformat});
-                $.ajax("/notebooks?" + qs, settings);
+                $.ajax('/notebooks?' + qs, settings);
             });
         var cancel_button = $('<button>Cancel</button>').button().
             click(function (e) {

IPython/nbformat/current.py

@@ -43,7 +43,7 b' def parse_py(s, **kwargs):'
     if m is not None:
         nbformat = int(m.group('nbformat'))
     else:
-        raise NBFormatError('No nbformat version found')
+        nbformat = 2
     return nbformat, s
 
 

IPython/nbformat/v2/nbpy.py

@@ -4,6 +4,10 b' from .rwbase import NotebookReader, NotebookWriter'
 from .nbbase import new_code_cell, new_worksheet, new_notebook
 
 
+class PyReaderError(Exception):
+    pass
+
+
 class PyReader(NotebookReader):
 
     def reads(self, s, **kwargs):
@@ -13,20 +17,42 b' class PyReader(NotebookReader):'
         lines = s.splitlines()
         cells = []
         cell_lines = []
+        code_cell = False
         for line in lines:
             if line.startswith(u'# <codecell>'):
+                if code_cell:
+                    raise PyReaderError('Unexpected <codecell>')
+                if cell_lines:
+                    for block in self.split_lines_into_blocks(cell_lines):
+                        cells.append(new_code_cell(input=block))
                 cell_lines = []
+                code_cell = True
             if line.startswith(u'# </codecell>'):
+                if not code_cell:
+                    raise PyReaderError('Unexpected </codecell>')
                 code = u'\n'.join(cell_lines)
                 code = code.strip(u'\n')
                 if code:
                     cells.append(new_code_cell(input=code))
+                code_cell = False
             else:
                 cell_lines.append(line)
+        # For lines we were not able to process, 
+        for block in self.split_lines_into_blocks(cell_lines):
+            cells.append(new_code_cell(input=block))
         ws = new_worksheet(cells=cells)
         nb = new_notebook(worksheets=[ws])
         return nb
 
+    def split_lines_into_blocks(self, lines):
+        import ast
+        source = '\n'.join(lines)
+        code = ast.parse(source)
+        starts = [x.lineno-1 for x in code.body]
+        for i in range(len(starts)-1):
+            yield '\n'.join(lines[starts[i]:starts[i+1]]).strip('\n')
+        yield '\n'.join(lines[starts[-1]:]).strip('\n')
+
 
 class PyWriter(NotebookWriter):
 

IPython/nbformat/v2/tests/test_nbpy.py

@@ -15,4 +15,3 b' class TestPy(TestCase):'
         s = writes(nb0)
         self.assertEquals(s,nb0_py)
 
-