How do I change the autoindent to 2 space in IPython notebook - jupyter-notebook

Question

I find that developing functions in IPython notebook allows me to work quickly. When I'm happy with the results I copy-paste to a file. The autoindent is 4 spaces, but the coding style for indentation at my company is 2 spaces. How do I change the autoindent to 2 spaces?

Answer 1

The official documentation has an example answering this specific question. This worked for me with IPython 4.
Summary: Paste the following into your browser's javascript console
var cell = Jupyter.notebook.get_selected_cell();
var config = cell.config;
var patch = {
CodeCell:{
cm_config:{indentUnit:2}
}
}
config.update(patch)
The setting is persisted. You can roll back by exchanging : 2 for : null.

Answer 2

From the official documentation for CodeMirror Code Cells:
Open an Ipython Notebook
Create a Code Cell e.g. by pressing b
Open your browser’s JavaScript console and run the following
snippet:
var cell = Jupyter.notebook.get_selected_cell();
var config = cell.config;
var patch = {
CodeCell:{
cm_config:{indentUnit:2}
}
}
config.update(patch)
Reload the notebook page in the browser e.g. by pressing F5
This will fix it permanently. I assume this works only on recent versions, not sure though!

Answer 3

AdamAL's answer is correct. It worked for me.
However it only changes the indentation in the Jupyter Notebook and leaves the indentation in the Jupyter Editor unaffected.
A more direct way to change the indentation is to directly edit the Jupyter config files in the .jupyter/nbconfig directory. This directory contains 2 files:
edit.json
notebook.json
The option you must set in either one is indentUnit. Here is the content of my Jupyter config files:
edit.json:
{
"Editor": {
"codemirror_options": {
"indentUnit": 2,
"vimMode": false,
"keyMap": "default"
}
}
}
notebook.json:
{
"CodeCell": {
"cm_config": {
"indentUnit": 2
}
}
}
With this approach I've set the default indentation to 2 in both the Jupyter Notebook and the Jupyter Editor.

Answer 4

Based on this question and the options found here:
In your custom.js file (location depends on your OS) put
IPython.Cell.options_default.cm_config.indentUnit = 2;
On my machine the file is located in ~/.ipython/profile_default/static/custom
Update:
In IPython 3 the plain call does not work any more, thus it is required to place the setting within an appropriate event handler. A possible solution could look like
define([
'base/js/namespace',
'base/js/events'
],
function(IPython, events) {
events.on("app_initialized.NotebookApp",
function () {
IPython.Cell.options_default.cm_config.indentUnit = 2;
}
);
}
);

Answer 5

If you use jupyterlab, there seems to be an easier way:
1) Click jupyterlab menu Settings > Advanced Setting Editor
2) Click "Notebook" on the left hand pane, make sure you are on "Raw View"
3) On the right pane, under "User Overrides", enter this:
{
"codeCellConfig": {
"tabSize": 2
}
}
If you look at the System Defaults, that will give you hint on whats overridable and you can repeat this for other settings.
I tried this on Google Platform AI Notebook which uses Jupyterlab.

Answer 6

I believe this is now best wrapped in a event handler to load once per notebook load:
$([IPython.events]).on('app_initialized.NotebookApp', function(){
IPython.CodeCell.options_default['cm_config']['indentUnit'] = 2;
});

Answer 7

In addition to adding
IPython.Cell.options_default.cm_config.indentUnit = 2;
to your custom.js file as suggested by Jakob, be sure to clear your browser cache as well before restarting ipython notebook!
Also, you may have to first create the ~/.config/ipython/profile_default/static/custom/ directory (use echo $(ipython locate default) to find your default directory) before adding the custom.js file.