No stdout from jupyter.runStartupCommands

Environment data

• VS Code version: 1.60.0
• Jupyter Extension version: v2021.8.2031190714
• Python Extension version: v2021.9.1191016588
• OS: Windows 10
• Python and/or Anaconda version: python 3.6.6 64-bit
• Type of virtual environment used: Winpython
• Jupyter server running: N/A

Expected behaviour (usecase 1)

put “print(‘startup’)” into the jupyter.runStartupCommands section of settings.json -> ‘startup’ should appear in the interactive window on generation of interactive window or on kernel restart.

Actual behaviour (usecase 1)

no output visible

Expected behaviour (usecase 2)

run the following script via jupyter.runStartupCommands in settings.json:

import asyncio

loop = asyncio.get_event_loop()

async def myTask():
    for i in range(10):
        print(f'{i} hello')
        await asyncio.sleep(1)

loop.create_task(myTask())

Should print to the interactive window every second, as it happens if the script is manually executed.

Actual behaviour (usecase 2)

No output visible at first. After the first input to the interactive window is executed, output appears. So I assume that some initialization of the stdout needs to take place.

Notes

Might be related to #5379

[IanMatthewHuff]

@lfriedri This was actually intentional on our side. The startup commands were intended to run silent at the start for any pre-configuration that was needed. However this might be work re-discussing. We’ll take about this at triage. Thanks for filing the issue.

[IanMatthewHuff]

Since your code is running async the output is just coming in on stdout from the python kernel. It only shows up when a cell exists in the UI to put the output into, which is why you see the behavior that you do. It’s a bit funky but I don’t think that it’s behavior that we will be changing now.