How can I configure indentation size in my Jupyter notebooks?

Question

I'd like to have a default indentation size of 2 spaces instead of 4 spaces in my Jupyter notebooks. How can I do this?

Note: this is not a duplicate of How do I change the autoindent to 2 space in IPython notebook, as that question is for (deprecated) IPython notebooks and not (current) Jupyter notebooks.

Answer 1

The correct way to do this is in bpirvu's buried answer to How do I change the autoindent to 2 space in IPython notebook:

Just edit ~/.jupyter/nbconfig/notebook.json. Here is a complete notebook.json which includes the relevant setting:

{
  "CodeCell": {
    "cm_config": {
      "indentUnit": 2
    }
  }
}

There's also a more hacky solution that's more prevalent around the web, probably because the Jupyter documentation is lacking on this topic and indentUnit is only mentioned here: http://jupyter-notebook.readthedocs.io/en/latest/frontend_config.html. This solution is to open your browser's JavaScript console and enter

var cell = Jupyter.notebook.get_selected_cell();
var config = cell.config;
var patch = {
      CodeCell:{
        cm_config:{indentUnit:2}
      }
    }
config.update(patch)

which ends up editing ~/.jupyter/nbconfig/notebook.json for you.