autoloading `.env` file format does not ignore inline comments.

[shellvon]

Recently, I discovered that projects opened via VSCode automatically load the .env file. Upon further investigation, I confirmed that the issue aligns with what was previously noted by #22982 .

In this context, I observed a particular detail: within VSCode, the .env file supports inline commenting capabilities.

Some other tools that handle env files also support inline comments:

• dotenv https://github.com/motdotla/dotenv/pull/568/files
• python-dotenv https://github.com/theskumar/python-dotenv?tab=readme-ov-file#file-format

When the .env file is processed by ms-python, such inline comment functionality is not recognized. Instead, ms-python leaves the commented parts of the file intact, treating them as part of the active configuration rather than ignoring them as comments.

vscode-python/src/client/common/variables/environment.ts

Lines 141 to 165 in 5fd5098

	function parseEnvLine(line: string): [string, string] {
	// Most of the following is an adaptation of the dotenv code:
	// https://github.com/motdotla/dotenv/blob/master/lib/main.js#L32
	// We don't use dotenv here because it loses ordering, which is
	// significant for substitution.
	const match = line.match(/^\s*(_*[a-zA-Z]\w*)\s*=\s*(.*?)?\s*$/);
	if (!match) {
	return ['', ''];
	}
	const name = match[1];
	let value = match[2];
	if (value && value !== '') {
	if (value[0] === "'" && value[value.length - 1] === "'") {
	value = value.substring(1, value.length - 1);
	value = value.replace(/\\n/gm, '\n');
	} else if (value[0] === '"' && value[value.length - 1] === '"') {
	value = value.substring(1, value.length - 1);
	value = value.replace(/\\n/gm, '\n');
	}
	} else {
	value = '';
	}
	return [name, value];

I believe this behavior can mislead many users because the UI suggests that it is a comment, yet the comments remain when loaded by this plugin. Without additional handling by the program, this can lead to peculiar results.

Perhaps we could maintain consistency with the regular expression found in the dotenv source code:

source from https://github.com/motdotla/dotenv/blob/8ab33066f90a20445d3c41e4fafba6c929c5e1a5/lib/main.js#L9

const LINE = /(?:^|^)\s*(?:export\s+)?([\w.-]+)(?:\s*=\s*?|:\s+?)(\s*'(?:\\'|[^'])*'|\s*"(?:\\"|[^"])*"|\s*`(?:\\`|[^`])*`|[^#\r\n]+)?\s*(?:#.*)?(?:$|$)/mg

[anthonykim1]

Hello @shellvon. Thank you for filing this issue. I appreciate the code reference and suggestion here.
If I am understanding correctly, is the comment part of your lines in .env file also being "activated" when the terminal activates and loads your environment variables in the .env file?

Would be curious to see how your environment variables look after the Python extension activates your terminal.
I assume #your comment would show up as part of printing environment variables??

[shellvon]

Yes, When using this extension, my code read SOME_VAR as "900" #inline comments (with inline comment) instead of "900". because this extension don't parse any inline comment

[brettcannon]

Ah, the joys of .env files not being a standard. 🙃

[github-actions]

Because we have not heard back with the information we requested, we are closing this issue for now. If you are able to provide the info later on, then we will be happy to re-open this issue to pick up where we left off.

Happy Coding!

[shellvon]

I think I've given enough information, it would be weird to just close it like this... @anthonykim1

[anthonykim1]

Hi @shellvon, yes I am reopening this. Please excuse the bot