ImportError: No module named notebook.notebookapp

For 4.0 and above You need to install the notebook app separately from https://github.com/jupyter/notebook

pip install jupyter

conda install jupyter will install latest jupyter along with other required dependencies

The following packages will be downloaded:

package                    |            build
---------------------------|-----------------
mistune-0.7                |           py27_0         186 KB
jinja2-2.8                 |           py27_0         263 KB
jupyter_core-4.0.3         |           py27_0          25 KB
tornado-4.2.1              |           py27_0         515 KB
jupyter_client-4.0.0       |           py27_0          88 KB
nbformat-4.0.0             |           py27_0         112 KB
ipykernel-4.0.3            |           py27_0         111 KB
nbconvert-4.0.0            |           py27_0         266 KB
jupyter_console-4.0.0      |           py27_0          22 KB
notebook-4.0.1             |           py27_0         4.2 MB
qtconsole-4.0.0            |           py27_0         120 KB
ipywidgets-4.0.2           |           py27_0          93 KB
jupyter-1.0.0              |           py27_0           2 KB
------------------------------------------------------------
                                       Total:         6.0 MB

This two commands will fix most problems for you:

sudo pip install --upgrade setuptools pip
sudo pip install --upgrade "ipython[all]"