Make cells (# %%) collapsible python files

[oerpli]

Environment data

• VS Code version: 1.33
• Extension version (available under the Extensions sidebar): Current
• OS and version: Win10 1703
• Python version (& distribution if applicable, e.g. Anaconda): Anaconda 3.7
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): Conda
• Relevant/affected Python packages and their versions: n/a

Expected behaviour

In a document with multiple cells, collapsing some of them improves usability.

Actual behaviour

It is not possible to collapse cells.

Some Details

I think defining #%% as (collapsible region start) shouldn't be very hard (I can try to submit a PR in 1-2 weekends if you agree with the idea).

Some implementation details should be evaluated though:

• Behavior of Shift+Enter in the cell above
• What to display if a region is collapsed (#%% Comment ... would be the default I think)
• Behavior of collapsed regions affected by Run below|above
• Visibility of Run Cell | Run Above | Run Below

[rchiodo]

I believe the only way to do this would be with the outline support VS Code has already: https://code.visualstudio.com/api/references/vscode-api#FoldingRangeProvider

As far as I can tell, the start line remains visible, so you'd probably end up with something like:

#%%

#%%

#%%

With no clear indication what cell was what. Maybe combined with a decorator provider, it could also stick in the first line of code after the cell header.

[diogo-rossi]

I am also waiting for this feature. It may be simple as described by @DonJayamanne in microsoft/vscode-python#10503

As far as I can tell, the start line remains visible, so you'd probably end up with something like:

#%%

#%%

#%%

With no clear indication what cell was what. Maybe combined with a decorator provider, it could also stick in the first line of code after the cell header

The feature may be very similar to the #region/#endregion folding, already supported (#33).
Like in #region folding, it could accept comments after key word that defines the cell.

[richarddwang]

Is there anything new ? This should be set to important because I believe most of data science and ml guys write long jupyter notebook. And we are used to collapse those cells in Colab.

[rchiodo]

Sorry but this isn't on our radar at the moment. It's waiting for more people to up vote it.

[BBirdselllab]

I upvoted. Both the other notebook platforms I use, Google Colabs & Mathematica, have this feature natively. The reasoning is sound: A lot of times in data sci applications certain cells are no longer required to be updated frequently and it reduces clutter. Not being able to collapse cells in VS Code's implementation of Jupyter notebooks has been being bugging me for months, and I was just thinking this weekend about porting some project files over to Colabs because it's a cleaner coding experience. It can't really be considered an edge feature request anymore. It's a minimal viable product requirement now in my opinion.

[Yannl]

I upvoted. It is the reason preventing me to use VSCode as a notebook editor.

The Microsoft team working on https://marketplace.visualstudio.com/items?itemName=ms-vscode.vscode-github-issue-notebooks already implemented collaspsible section as well as drag and drop of cells in notebooks. (cf screenshot or VSCode insider required to test for now) Could you reuse their work?

[rchiodo]

The Microsoft team working on https://marketplace.visualstudio.com/items?itemName=ms-vscode.vscode-github-issue-notebooks already implemented collaspsible section as well as drag and drop of cells in notebooks. (cf screenshot or VSCode insider required to test for now) Could you reuse their work?

Yes this is the plan. We'll be using that same API to rewrite how we support jupyter notebooks.

[mmcguffi]

Is there any update on this? I agree with previous comments that this is a huge headache when using VScode for Jupyter notebooks

[DonJayamanne]

For those interested, our long term plan is to use the VS Code Notebook API for Jupyter Notebooks. More information can be found here: https://github.com/microsoft/vscode-python/issues/10496 https://github.com/microsoft/vscode-python/issues/12189

[rchiodo]

It should be noted that this issue microsoft/vscode-python#5227 is actually about adding another collapse region into a python file with cells. Cells are usually delineated with # %%.

This issue is not actively being pursued by our team but we welcome PRs if somebody else finds the time to get to this.

[PrateekArya]

@rchiodo Not sure if u are joking or serious but I think the original request was about collapsing the cells only. 😊

Also, isn't this same as microsoft/vscode-python#10503 and microsoft/vscode-jupyter#957??

For those who are very desperate can type "if True:" on the top of the cells which you want to hide. Then u can fold them. It is surely not very efficient but it will serve the purpose for the time being. 😉

[rchiodo]

@PrateekArya not sure what you are wondering what I'm joking about? Submitting PRs? External contributors have done a bunch of work in the past. Collapsable regions is not high on our backlog at the moment but if somebody else really wants it, we would certainly love any submission.

I believe the solution to this request would be to add a FoldingRangeProvider: https://code.visualstudio.com/api/references/vscode-api#FoldingRange

In our code where we create code lenses, it probably wouldn't be too hard to add a folding range provider somewhere there.

[DonJayamanne]

For anyone interested here's a sample implementation (created for folding of docstrings). We'd just need to identify cell markers (we have code for that too - to get the cell ranges). We're happy to help anyone who wants to take a stab at this.

https://github.com/microsoft/vscode-python/blob/7c81cfcd06cdbfd91224489864ac3c9ae2c16d59/src/client/providers/docStringFoldingProvider.ts#L1-L2

[diogo-rossi]

@PrateekArya

For those who are very desperate can type "if True:" on the top of the cells which you want to hide. Then u can fold them. It is surely not very efficient but it will serve the purpose for the time being. 😉

I think it is better to use the region/endregion comment approach, which is somehow official. Use if True: may lead to indentation erros in some cases . . .

Sorry, I really thought this issue was easy to provide (replacing region/endregion for two %% in sequence)

[pythlang]

Temp comment bump for now as I've just stumbled across this while working and also desire this... I may be able to take a stab at this in a few weeks here with some guidance while I have some free time.

Let me get back to this comment later.

[retorquere]

I believe the only way to do this would be with the outline support VS Code has already: https://code.visualstudio.com/api/references/vscode-api#FoldingRangeProvider

As far as I can tell, the start line remains visible, so you'd probably end up with something like:

#%%

Would # %% # some comment work?

[ruestefa]

Would # %% # some comment work?

You can add comments directly after # %% even without an additional #.

[chenhao1umbc]

It has been more than 2 years, since the original post...

[diogo-rossi]

For anyone still waiting for this (like me), I found a way that worked for me. It is the simple setting bellow (in case it help someone):

Expand the "Regular expression used to identify code cells" (in the settings) to also recognize the expression #\\s*region

"jupyter.codeRegularExpression": "^(#\\s*%%|#\\s*\\<codecell\\>|#\\s*In\\[\\d*?\\]|#\\s*In\\[ \\]|#\\s*region)" <- here

Now the cells also starts with # region and I can close the folding area with # endregion, making the cells collapsible.

[PrateekArya]

Yes, it works! But I am using a modified version as follows so that I can also write comments on the top of my cells:

Here if u just want to copy it: ^(#\s*region\s*%%|#\s*\<codecell\>|#\s*In\[\d*?\]|#\s*In\[ \])

Now, I write the cell headers as:

and the end of cell and starting of next cell as:

My folded cells looks like this:

[diogo-rossi]

@PrateekArya

Nice! But just to make it clear: you regular expression requires that the cell starts with # region %%.

Basically, you have not added a new pattern but modified the regular # %% to # region %%.

That is ok. But if you find working with some file with the previous pattern %% that won't be a cell anymore.

BTW, any of that patterns allow you to write comments on the top of cells.

[PrateekArya]

Yes. I agree! :)

[ghost]

@Diogo-Rossi Thanks your fix works...I am currently using VSCode Insider V.1.60. Accidently I was able to make the usual # %% collapsible. Write # %% + press enter + tab + # region.

"# %%" folding works...

[greazer]

Really creative and interesting! Given the above you could take it to the next step and create a snippet.

1. Ctrl+Shift+P -> Preferences: Configure User Snippets
2. Pick a snippet config
3. Use this as a snippet...

"Collapsible Python Cell": {
"scope": "python",
"prefix": "cc",
"body": [
	"# %%",
	"	# region",
	"$0"
	"   # endregion"
],
"description": "Insert a collapsible pythoh cell for execution in the Interactive Window"
}

4. Use the snippet with Ctrl+Space, cc, <enter>

It's not the perfect solution, and you'll probably want to turn off the setting Jupyter: Collapse Cell Input Code By Default, but until we are able to create (or receive) a PR to bring a first-class experience, it may get you by.

[diogo-rossi]

I found a better solution. Maybe you are interesting too.

1. Install this extension
2. Config the setting "editor.foldingStrategy" to "auto" (i.e.: "editor.foldingStrategy":"auto")
3. Add the following in the settings:

"explicitFolding.rules": {
    "python": [
        {
            "separatorRegex": <PUT HERE THE SAME REGEX USED IN THE SETTING "jupyter.codeRegularExpression">
            "foldEOF":true
        },
        {
            "indentation": true,
            "offSide": true
        }
    ]
}

Now everything works.

• All the expressions used in "jupyter.codeRegularExpression" define cells that are collapsible. (including #%%)
• There is no need of any additional line (i.e. # endregion) to close the collapsible regions.
• It now works exactly the same as the cells in spyder

[rebornix]

@Diogo-Rossi thanks for the solution, it works seamlessly.

"explicitFolding.rules": {
        "python": [
            {
                "separatorRegex": "# %%",
                "foldEOF":true
            }
        ]
    }

We could probably register a similar folding range provider in Jupyter oob.

[otaolafranc]

Hello, doing what was mentionned above, added the possibility to fold using "# %%" but it removed the possibility to fold for functions (def) or (for). anyone that could give me a hand to solve this issue?

I found a better solution. Maybe you are interesting too.

1. Install this extension
2. Config the setting "editor.foldingStrategy" to "auto" (i.e.: "editor.foldingStrategy":"auto")
3. Add the following in the settings:

"explicitFolding.rules": {
    "python": [
        {
            "separatorRegex": <PUT HERE THE SAME REGEX USED IN THE SETTING "jupyter.codeRegularExpression">
            "foldEOF":true
        },
        {
            "indentation": true,
            "offSide": true
        }
    ]
}

Now everything works.

• All the expressions used in "jupyter.codeRegularExpression" define cells that are collapsible. (including #%%)
• There is no need of any additional line (i.e. # endregion) to close the collapsible regions.
• It now works exactly the same as the cells in spyder

[diogo-rossi]

@otaolafranc It seems we don't need this suggestion anymore to fold using #%%. It is now part of the extension.