ipykernel 7.0.1 - Jupyter autocomplete delay

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
jupyter, jupyter-notebook, python
Domain
developer-experience

Research direction

Reproduce the delay in VS Code with a Jupyter notebook using import pandas as pd, then compare ipykernel 7.0.1 with 6.30.1 and verify that regular .py files remain unaffected. Trace the notebook autocomplete path to identify where the 2–3 second delay occurs; done means suggestions appear promptly without regressing normal Python-file completion.

Written by the indexing model from the issue text.

Description

Issue:
When using VS Code with the Jupyter extension, triggering autocomplete (Ctrl + Space) inside a notebook cell causes a noticeable delay (~2–3 seconds). This only happens in Jupyter notebooks, regular .py files are unaffected.

Steps to reproduce:

  1. Open a Jupyter notebook in VS Code.
  2. Import any Python module (e.g., import pandas as pd).
  3. Inside a new cell, type something like pd. and press Ctrl + Space.
  4. Observe a 2–3 second delay before suggestions appear.

Expected behavior:
Autocomplete should appear instantly, as it does in .py files.

Reverting ipykernel to version 6.30.1 immediately fixes the issue.

Dominant language
Python
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Forks
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Avg merge
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Merged PRs (30d)
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