nbopen doesn't create file it it doesn't exist

[ctb]

e.g.
nbopen foo.ipynb opens the JupyterLab interface if foo.ipynb doesn't exist, instead of creating it.

Ideally, it would create an empty file of that name and then open it with jupyter. I bet the tricky bit is that you have to guess at the format of the file based on the name...

[ctb]

Whups! Realized -n/--new does this just fine! I feel like this could/should be the default tho?

[takluyver]

Yup, it should either create the file, or fail consistently with a short, clear error message. At present, it fails with a load of Jupyter messages ending in a reasonable error if there isn't a server running, and opens a 404 page if there is.

I'll have a think about which I prefer.

[ctb]

I like creating the file, personally. I will see if I can hack on this and submit a PR!

[takluyver]

It should be pretty straightforward :-). If you can get a PR in before I've decided what I prefer, I'll go with what you want.