Hi @jonmatthis

Thanks so much for this PR. I always thought pyqtgraph's console example probably wasn't that great and we would better serve our users by showing how to better integrate jupyter consoles or the qtconsole.

A couple of small issues I see, seems like the formatting isn't quite right, I think you may have a tab instead of spaces in one place and such; you may want to runblack on the new-file.

Also in pyqtgraph/examples/utils.py you reference a file that doesn't exist, but in this PR you add the file to pyqtgraph/widgets/.... I'm not sure if you forgot to include the example file, or if the file in the widgets directory should be in the examples.

EDIT: while I have no problem adding type-hints, to the code-base (eventually want to do that anyway)

Nifty! I imagine updating the kernel's namespace would be a fairly common operation; would you consider adding a method similar to pushVariables from this SO answer? I would also support adding a namespace argument to the constructor for this reason, like the old ConsoleWidget

Whoops, I forgot to add the example file to git. I think I just did that?

I'll go through your other comments now, thanks!

Nifty! I imagine updating the kernel's namespace would be a fairly common operation; would you consider adding a method similar to pushVariables from this SO answer?

I agree that's very useful! I added that method and showed and sample usage in the example

I would also support adding a namespace argument to the constructor for this reason, like the old ConsoleWidget

I did this too, I'm not 100% clear on the concept of a 'namespace' so it's possible I missed something important :)

Hi @jonmatthis

Thanks for updating the PR. I'm reluctant to add code here to pyqtgraph/widgets, I think this is small enough, the entirety can live as an example.

In the discord chat, @pijyoi was kind enough to make a suggestion for what an example could look like:

import numpy as np
import pyqtgraph as pg
from pyqtgraph.Qt import QtWidgets
from qtconsole import inprocess

class ConsoleWidget(inprocess.QtInProcessRichJupyterWidget):
    def __init__(self):
        super().__init__()
        
        self.kernel_manager = inprocess.QtInProcessKernelManager()
        self.kernel_manager.start_kernel()
        self.kernel_client = self.kernel_manager.client()
        self.kernel_client.start_channels()

    def shutdown_kernel(self):
        self.kernel_client.stop_channels()
        self.kernel_manager.shutdown_kernel()

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        cwidget = QtWidgets.QWidget()
        vbox = QtWidgets.QVBoxLayout()
        cwidget.setLayout(vbox)
        self.plot = pg.PlotWidget()
        self.console = ConsoleWidget()
        vbox.addWidget(self.plot)
        vbox.addWidget(self.console)
        self.setCentralWidget(cwidget)

        app = QtWidgets.QApplication.instance()
        app.aboutToQuit.connect(self.console.shutdown_kernel)

        kernel = self.console.kernel_manager.kernel
        kernel.shell.push(dict(np=np, pw=self.plot))
        self.console.execute("whos")

if __name__ == '__main__':
    pg.mkQApp()
    main = MainWindow()
    main.show()
    pg.exec()

There is some president here for demonstrating functionality in the examples that isn't really a part of the library directly, specifically the GLPainter example comes to mind.

I agree with this! It demonstrates the method to get a jupyter console widget, while keeping responsibility for maintaining that core functionality of that widget in the hands of the qtconsole folks, which is more appropriate

A few suggested tweaks to that example to make it a bit more transparent to low-XP folks (like me😅).

It's mostly just changing the variable names to make it (even) more obvious which variable is what, and an example of how to execute a command after creating the Widget.

Other potential cool additions would be -

• show sample inputs to plot something simple in that Plot window
• Adding a very simple paramter_tree widget that shows the variables returned by whos

import numpy as np
import pyqtgraph as pg
from pyqtgraph.Qt import QtWidgets
from qtconsole import inprocess


class JupyterConsoleWidget(inprocess.QtInProcessRichJupyterWidget):
    def __init__(self):
        super().__init__()

        self.kernel_manager = inprocess.QtInProcessKernelManager()
        self.kernel_manager.start_kernel()
        self.kernel_client = self.kernel_manager.client()
        self.kernel_client.start_channels()

    def shutdown_kernel(self):
        self.kernel_client.stop_channels()
        self.kernel_manager.shutdown_kernel()


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        central_widget = QtWidgets.QWidget()
        vbox_widget = QtWidgets.QVBoxLayout()
        central_widget.setLayout(vbox_widget)
        self.plot_widget = pg.PlotWidget()
        self.console = JupyterConsoleWidget()
        vbox_widget.addWidget(self.plot_widget)
        vbox_widget.addWidget(self.console)
        self.setCentralWidget(central_widget)

        app = QtWidgets.QApplication.instance()
        app.aboutToQuit.connect(self.console.shutdown_kernel)

        kernel = self.console.kernel_manager.kernel
        kernel.shell.push(dict(np=np, pw=self.plot_widget))
        self.console.execute("whos")


if __name__ == '__main__':
    pg.mkQApp()
    main = MainWindow()
    main.show()
    main.console.execute("print(\"hello world :D \")")
    pg.exec()

Nice, in the PR there was an example of how to incorporate dark mode; can that be easily done?

sorry for the delay! I'll test this on my end later today, but I suspect that I'll be totally happy with this option :D

Ok, I think I removed my previously committed changes (but please double check I didn't miss anything)

To summarize changes:

Per the conversation above, I removed the standalong "JupyterConsoleWidget" in favor of a more fleshed out example that implements such a console based on the qtconsole project's examples laid out here: https://github.com/jupyter/qtconsole/tree/b4e08f763ef1334d3560d8dac1d7f9095859545a/examples

The new example creates a RichJupyterConsole Widget alongside a PlotWidget, and then shows an example of a way to plot simple sine/cosine waves by entering commands from the __main__ function of the example.

The widgets are implements as Docks so that Users can re-size the windows and close the PlotWidget if they want to.

The example was added to the list of examples in examples/utils.py

I tagged it as a 'recommended' example, but I'm totally happy to remove that if that doesn't feel appropriate.

Please let me know if there is anything else I can do to help move this forward :D

Hi @jonmatthis

Thanks for updating the PR, sorry it's taken me a bit to get to this.

I added an inline comment about inserting a newline in .gitignore; the other thing is I think you need to remove pyqtgraph/examples/jupyterConsoleWidgetExample.py as that used the JupyterConsoleWidget class in pyqtgraph.widgets which is no longer present.

Also the dark mode is 🔥

Ok, done!

I knew I was forgetting something 😅

Ok, did the things 👍

Do we want to add this example into conditionalExamples in https://github.com/pyqtgraph/pyqtgraph/blob/master/pyqtgraph/examples/test_examples.py#L68 in order to avoid a CI dependency on qtconsole?

Do we want to add this example into conditionalExamples in https://github.com/pyqtgraph/pyqtgraph/blob/master/pyqtgraph/examples/test_examples.py#L68 in order to avoid a CI dependency on qtconsole?

Completely forgot about conditionalExamples, thanks for the reminder @pijyoi this would certainly qualify.

blerg, need to indicate to skip this example when qtconsole is not installed; sorry should have caught this earlier sorry about that!

Anyway, you need to add an entry here:

https://github.com/pyqtgraph/pyqtgraph/blob/master/pyqtgraph/examples/test_examples.py#L68-L77

You'll want to add something like

    "jupyter_console_example.py": exceptionCondition(
        importlib.util.find_spec("qtconsole") is not None,
        reason="No need to test with qtconsole not being installed"
    ),

Hi @jonmatthis I hope you don't mind, I added that last bit to make the examples pass; I should have given you that feedback weeks ago, sorry about that. Anyway, this looks good to merge. Thanks for the PR!

Hey cool!! This is my first PR into an open source project :D

Thank you for all your great work maintaining this incredible package, and for making this PR experience easy, fun, and educational <3

Congratulations on your first PR! Appreciate the sentiment, we certainly could have done better by giving you reviews/suggestions in a more timely manner, sorry about that!