Browser communication with Jupyter Python kernel

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Christopher Brooks

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Nov 11, 2016, 7:19:09 PM11/11/16
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Hi,

I'm trying to do a bit of rapid prototyping of a jupyter javascript extension which invokes services against a python kernel. The docs take some serious time, but what I've groked is that there are a set of REST-based services which I call, but it seems like these services do not allow me to push code to the kernel, just identify which kernels and sessions are available. It seems instead that once I have identified a kernel, I can use this wire protocol for interaction with the kernel. However, I'm unclear which endpoint to push messages to and feel like there must be a browser-based Javascript library available for this purpose. COMMs caught my eye, but again, it seems like it should be more straight forward to push some python strings to a kernel and observe the results. The JupyterLab Services looked promising, but it's all Node.jsified, which makes me think this is the wrong tree to bark down.

Maybe someone could give me a gentle nudge in the right direction?

(I sort of expected something as trivial as an IPython.Notebook.execute("somecode")....)

Regards,

Chris

MinRK

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Nov 12, 2016, 4:39:06 PM11/12/16
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JupyterLab services is for use in the browser, that’s what JupyterLab uses to talk to these APIs. If you are already in the existing pre-Lab notebook and want to run code on the current kernel, the API you are after is:

Jupyter.notebook.kernel.execute("some code", callbacks)

-MinRK

​

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Christopher Brooks

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Nov 12, 2016, 5:39:12 PM11/12/16
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Wonderful, thanks very much MinRK. Is callbacks just a function which takes a single parameter, or are there docs on this api which I have overlooked?

Chris


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MinRK

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Nov 18, 2016, 7:52:23 AM11/18/16
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On Sat, Nov 12, 2016 at 11:39 PM, Christopher Brooks <broo...@umich.edu> wrote:

Wonderful, thanks very much MinRK. Is callbacks just a function which takes a single parameter, or are there docs on this api which I have overlooked?

callbacks is a structure for different types of callbacks. Its shape is described here.

-Min

​

Doug Blank

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Nov 18, 2016, 8:05:47 AM11/18/16
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On Friday, November 18, 2016 at 7:52:23 AM UTC-5, Min RK wrote:

On Sat, Nov 12, 2016 at 11:39 PM, Christopher Brooks <broo...@umich.edu> wrote:

Wonderful, thanks very much MinRK. Is callbacks just a function which takes a single parameter, or are there docs on this api which I have overlooked?

callbacks is a structure for different types of callbacks. Its shape is described here.


I'm working with some code that calls this as well. Are the standard callbacks (for print, error handling, display, etc) available to plugin in here? It would be handy to have the standard callbacks available, or to be able to slightly alter/replace particular ones (eg, dispay). 

-Doug

 

-Min

Chris


On Nov 12, 2016 4:39 PM, "MinRK" <benja...@gmail.com> wrote:

JupyterLab services is for use in the browser, that’s what JupyterLab uses to talk to these APIs. If you are already in the existing pre-Lab notebook and want to run code on the current kernel, the API you are after is:

Jupyter.notebook.kernel.execute("some code", callbacks)

-MinRK

​
On Fri, Nov 11, 2016 at 4:19 PM, Christopher Brooks <broo...@umich.edu> wrote:
Hi,

I'm trying to do a bit of rapid prototyping of a jupyter javascript extension which invokes services against a python kernel. The docs take some serious time, but what I've groked is that there are a set of REST-based services which I call, but it seems like these services do not allow me to push code to the kernel, just identify which kernels and sessions are available. It seems instead that once I have identified a kernel, I can use this wire protocol for interaction with the kernel. However, I'm unclear which endpoint to push messages to and feel like there must be a browser-based Javascript library available for this purpose. COMMs caught my eye, but again, it seems like it should be more straight forward to push some python strings to a kernel and observe the results. The JupyterLab Services looked promising, but it's all Node.jsified, which makes me think this is the wrong tree to bark down.

Maybe someone could give me a gentle nudge in the right direction?

(I sort of expected something as trivial as an IPython.Notebook.execute("somecode")....)

Regards,

Chris

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MinRK

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Nov 18, 2016, 8:25:29 AM11/18/16
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On Fri, Nov 18, 2016 at 2:05 PM, Doug Blank <doug....@gmail.com> wrote:

On Friday, November 18, 2016 at 7:52:23 AM UTC-5, Min RK wrote:

On Sat, Nov 12, 2016 at 11:39 PM, Christopher Brooks <broo...@umich.edu> wrote:

Wonderful, thanks very much MinRK. Is callbacks just a function which takes a single parameter, or are there docs on this api which I have overlooked?

callbacks is a structure for different types of callbacks. Its shape is described here.


I'm working with some code that calls this as well. Are the standard callbacks (for print, error handling, display, etc) available to plugin in here? It would be handy to have the standard callbacks available, or to be able to slightly alter/replace particular ones (eg, dispay). 

There are separate callbacks for each cell (this is how output is routed to different cells for different requests). You can get the default callbacks for a given code cell with cell.get_callbacks().

-MinRK

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Doug Blank

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Nov 18, 2016, 9:01:34 AM11/18/16
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Perfect!

-Doug

Doug Blank

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Jan 16, 2017, 6:15:47 PM1/16/17
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On Sat, Nov 12, 2016 at 4:38 PM, MinRK <benja...@gmail.com> wrote:

JupyterLab services is for use in the browser, that’s what JupyterLab uses to talk to these APIs. If you are already in the existing pre-Lab notebook and want to run code on the current kernel, the API you are after is:

Jupyter.notebook.kernel.execute("some code", callbacks)

-MinRK

This is a very handy indeed:

cell = Jupyter.notebook.get_cell(0) ; // cell number
Jupyter.notebook.kernel.execute("%python print(42)", cell.get_callbacks())

But what if you want to use Javascript to generate the message (rather than the kernel) to print to the cell? Is there an easy method to do that?

-Doug

 
​

On Fri, Nov 11, 2016 at 4:19 PM, Christopher Brooks <broo...@umich.edu> wrote:
Hi,

I'm trying to do a bit of rapid prototyping of a jupyter javascript extension which invokes services against a python kernel. The docs take some serious time, but what I've groked is that there are a set of REST-based services which I call, but it seems like these services do not allow me to push code to the kernel, just identify which kernels and sessions are available. It seems instead that once I have identified a kernel, I can use this wire protocol for interaction with the kernel. However, I'm unclear which endpoint to push messages to and feel like there must be a browser-based Javascript library available for this purpose. COMMs caught my eye, but again, it seems like it should be more straight forward to push some python strings to a kernel and observe the results. The JupyterLab Services looked promising, but it's all Node.jsified, which makes me think this is the wrong tree to bark down.

Maybe someone could give me a gentle nudge in the right direction?

(I sort of expected something as trivial as an IPython.Notebook.execute("somecode")....)

Regards,

Chris

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Doug Blank

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Jan 16, 2017, 8:23:58 PM1/16/17
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I have some working code:

function(message) {
    Jupyter.notebook.get_cell(0).get_callbacks().iopub.output({header: {"msg_type": "stream"},
      content: {text: message + "\n",
name: "stdout"}})
};

Is there anything better?

-Doug
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