Smarter assistant python pkg install

[nstrayer]

Addresses #8174.

Adds a new installPythonPackage tool that enables the Assistant to directly install Python packages instead of suggesting !pip commands that don't work in Positron's environment. The Assistant can now handle package installation requests by invoking the appropriate package manager (pip, uv, conda) through the integrated tool.

Note: This may be way too intense of a fix for a simple behavior change. Not at all married to the whole new tool at all.

Release Notes

New Features

• N/A

Bug Fixes

• Assistant can now directly install Python packages instead of suggesting non-functional
  !pip commands

QA Notes

Ask the Assistant to install Python packages like palmerpenguins and plotnine. The Assistant should now use the built-in installation tool rather than suggesting !pip commands.

Test in assistant

# Ask: "Install palmerpenguins and plotnine for me"
# Expected: Assistant uses the installPythonPackage tool to install packages directly
# Packages should be installed successfully without user needing to run terminal commands

The Assistant should no longer suggest !pip install commands and instead handle package installation automatically using the new tool.

[github-actions]

E2E Tests 🚀
This PR will run tests tagged with: @:critical

^{readme  valid tags}

[jmcphers]

This did not work for me locally.

This is a Python 3.11 environment with uv venv. Would you expect that to work?

[nstrayer]

Weird. I tested it with uv and python 3.12. Alas. I'll look into it tomorrow!

[nstrayer]

I can't reproduce.

[Copilot]

Pull Request Overview

This PR enables the Assistant to install Python packages directly by introducing a new command handler in the Positron Python extension and wiring it up as an Assistant tool instead of relying on !pip suggestions.

• Adds InstallPackagesCommandHandler to handle python.installPackages in Positron Python.
• Registers a new installPythonPackage tool in the Assistant that invokes this command.
• Updates prompts, types, and metadata to guide the Assistant to use the new workflow.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
extensions/positron-python/src/client/common/serviceRegistry.ts	Import and register InstallPackagesCommandHandler
extensions/positron-python/src/client/common/constants.ts	Added InstallPackages command constant
extensions/positron-python/src/client/common/application/commands/installPackages.ts	Implemented InstallPackagesCommandHandler
extensions/positron-python/src/client/common/application/commands.ts	Mapped Commands.InstallPackages to [string[]] args
extensions/positron-python/package.json	Added “Install Python Packages” command entry
extensions/positron-assistant/src/types.ts	Defined InstallPythonPackage tool name
extensions/positron-assistant/src/tools.ts	Registered installPythonPackage tool
extensions/positron-assistant/src/md/prompts/chat/instructions-python.md	Added Python package installation rules and examples
extensions/positron-assistant/package.json	Declared metadata for installPythonPackage tool

Comments suppressed due to low confidence (2)

extensions/positron-python/src/client/common/application/commands/installPackages.ts:14

• Add a class-level JSDoc comment for InstallPackagesCommandHandler to explain its purpose and activation behavior.

@injectable()

extensions/positron-python/src/client/common/application/commands/installPackages.ts:1

• No unit tests have been added for InstallPackagesCommandHandler; consider adding tests covering input validation, installer absence, and success/failure flows.

/*---------------------------------------------------------------------------------------------

[Copilot]

[nitpick] Installing packages sequentially can be slow for multiple items; consider running installs in parallel (e.g., with Promise.all) and aggregating results.

Suggested change

	for (const packageName of packages) {
	try {
	await installer.installModule(packageName, undefined, undefined, ModuleInstallFlags.none, undefined);
	results.push(`${packageName} installed successfully using ${installer.displayName}`);
	} catch (error) {
	const errorMsg = error instanceof Error ? error.message : String(error);
	results.push(`${packageName}: Installation failed - ${errorMsg}`);
	// Continue with next package to provide complete installation report
	}
	}
	const installationPromises = packages.map(async (packageName) => {
	try {
	await installer.installModule(packageName, undefined, undefined, ModuleInstallFlags.none, undefined);
	return `${packageName} installed successfully using ${installer.displayName}`;
	} catch (error) {
	const errorMsg = error instanceof Error ? error.message : String(error);
	return `${packageName}: Installation failed - ${errorMsg}`;
	}
	});
	const settledResults = await Promise.allSettled(installationPromises);
	results.push(...settledResults.map((result) => (result.status === 'fulfilled' ? result.value : '')));

[jmcphers]

I did some debugging and found that the problem was that I had no pip in my uv environment. I don't know enough about uv to know if this is normal or not. It does work once I have pip installed!

Python 3.11.12 (Uv: .venv) started.
Python 3.11.12 (main, May 22 2025, 01:39:08) [Clang 20.1.4 ]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.18.1 -- An enhanced Interactive Python. Type '?' for help.
Automatic import reloading for Python is enabled. It can be disabled with the [python.enableAutoReload setting](vscode-file://vscode-app/Users/jmcphers/git/positron/out/vs/code/electron-sandbox/workbench/workbench-dev.html#).
>>> pip
/Users/jmcphers/data/errata/.venv/bin/python: No module named pip
Note: you may need to restart the kernel to use updated packages.

My only other feedback is that the tool returns (and declares success) after it initiates the package install, but before the packages are actually installed. This means it won't be able to help troubleshoot installation errors and may presume that the packages are installed later in the conversation when they aren't. Still an improvement over what we have today, though!

[nstrayer]

Updated so that the tool knows the result of the install command.