Launching a notebook from a notebook

Part 1 (2018)
1

I am trying to control a jupyter notebook ("Notebook1.ipynb") from another jupyter notebook("Notebook2.ipynb") . Everything works fine, except the cell which opens the second notebook never returns, even after halting and closing the tab.

  1. The contents of “Notebook1.ipynb”:

    In [1] !runipy Notebook2.ipynb OutputNotebook.ipynb

    In [*] !jupyter notebook ./OutputNotebook.ipynb

     [I 13:54:47.711 NotebookApp] The port 8888 is already in use, trying another port.
 [I 13:54:47.717 NotebookApp] Serving notebooks from local directory: /home/user/Documents/testing_jupyter
 [I 13:54:47.717 NotebookApp] 0 active kernels
 [I 13:54:47.718 NotebookApp] The Jupyter Notebook is running at:
 [I 13:54:47.718 NotebookApp] http://localhost:8889/?token= [REMOVED] 
 [I 13:54:47.718 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
 [C 13:54:47.718 NotebookApp] 
 	
 	Copy/paste this URL into your browser when you connect for the first time,
 	to login with a token:
 		http://localhost:8889/?token= [REMOVED] 
 [I 13:54:47.916 NotebookApp] Accepting one-time-token-authenticated connection from 127.0.0.1
 [W 13:54:48.778 NotebookApp] Notebook OutputNotebook.ipynb is not trusted
 [I 13:54:48.951 NotebookApp] Kernel started: [REMOVED]
 [I 13:54:49.579 NotebookApp] Adapting to protocol v5.1 for kernel [REMOVED]
 [I 13:55:13.839 NotebookApp] Starting buffering for [REMOVED]:[REMOVED]
 [I 13:55:14.143 NotebookApp] Kernel shutdown: [REMOVED]
 [W 13:55:27.569 NotebookApp] 404 DELETE /api/sessions/[REMOVED](127.0.0.1): Session not found: session_id='[REMOVED]'
 [W 13:55:27.570 NotebookApp] Session not found: session_id='[REMOVED]'
 [W 13:55:27.570 NotebookApp] 404 DELETE /api/sessions/[REMOVED] (127.0.0.1) 2.06ms     referer=http://localhost:8889/notebooks/OutputNotebook.ipynb

 In [*] print("back")

  2. The contents of “Notebook2.ipynb”:

    [ ] print("Wow!")

  3. The contents of “OutputNotebook.ipynb”:

    In [1] print(“Wow!”)

Any ideas?

2

I tired to do stuff with subprocess, but the best I can figure out is to call:

!firefox http://127.0.0.1:8888/notebooks/OutputNotebook.ipynb

which returns immediately, but is the only method I can find that actually will halt the kernel if selected in the launched tab.