Codefolding
This extension adds codefolding functionality from CodeMirror to a codecell. This functionality requires the current master version of IPython or installing a more recent version of CodeMirror for 1.x versions of IPython.
After clicking on the gutter (left margin of codecell) or typing Alt+F, the code gets folded. See the examples below. The folding status is saved in the cell metadata of the notebook, so reloading of a notebook will restore the folding view.
Three different folding modes are supported.
Python-style code folding, detetects indented code.
The unfolded code above can be folded like this:
or this:
Other languages like Javascript use brackets to designate code blocks. Codefolding is supported for Javascript in using the %%javsscript magic in a codecell.
Allows collapsing of Python code cells to a single comment line. This is useful for long codecells. The algorithm simply looks for a comment in the first line and allows folding in the rest of the cell.
The code above can be folded like this:
Copy the codefolding directory to a new /static/custom/codefolding directory of your IPython profile and add
require(['/static/custom/codefolding/codefolding.js'])to your custom.js file so it looks like this:
$([IPython.events]).on('app_initialized.NotebookApp', function(){
//...
require(['/static/custom/codefolding/codefolding.js'])
});If you use the current master branch of IPython from GitHub, this is all you need to do.
For the 1.x versions of IPython, you need to download a recent version of Codemirror from http://codemirror.net and install it in your local profile under /static/custom/components/codemirror.
You need the current master branch from Codemirror in order to get codefolding to work. This is still very much work-in-progress.
The folding information is saved in the metadata of each codecell. The number of the folding start line (beginning with 0) is stored in an array:
cell.metadata.code_folding = [ 3, 20, 33 ]When reloading the IPython notebook, the folding status is restored.