Without line numbers, debugging syntax errors in large documents is a tedious and painful process.

Thanks for the patch, Steve!.

This looks like a reasonable request to me, but 1) we can only make this change in 3.7 2) we need a test case for the new message 3) you can use f-strings instead of str.format()

Usually literal_eval() is used with short one-line input. For what large documents do you use it?

We're using Python dictionaries to express sizeable (read: 100-600 lines)
chunks of configuration data. We previously used JSON, but we now use
Jinja2 to template chunks of this configuration data, and JSON's inability
to handle trailing commas creates a problem here. So we've been using
ast.literal_eval, but the lack of line numbers makes debugging problems
with the configurations a painful process.

On Sun, Jan 1, 2017 at 2:41 AM Serhiy Storchaka <report@bugs.python.org>
wrote:

>
> Serhiy Storchaka added the comment:
>
> Usually literal_eval() is used with short one-line input. For what large
> documents do you use it?
>
> ----------
> nosy: +serhiy.storchaka
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <http://bugs.python.org/issue28964>
> _______________________________________
>

Steve, will you work on this patch to GitHub?

I'll try to get to it this weekend. A bit swamped on another project right now. Thanks for the interest and the reminder!

Steve, are you planning to work on porting this patch to github?

Note: it would need a unit test, and also node is not guaranteed to have a lineno field.

> Usually literal_eval() is used with short one-line input. For what large documents do you use it?

I kind of agree with Serhiy on this, nearly every use case I've encountered was simple, single-line expression. Though, by seeing Irit's patch I think the implementation is reasonable enough to do.

This just came up again in issue42561 so I went ahead and created the PR.

I'm +0 on this (even though we only had 2 users wanting this, the implementation seems very trivial). @serhiy.storchaka, @pablogsal any opinions?

This is a recurring feature request (I have heard people asking for this a couple of times) and is simple enough to do, so I am fine with this. Unless Serhiy has some concern, I would go forward :)

New changeset 586f3dbe15139cafb2a6ffb82cea146906561844 by Irit Katriel in branch 'master':
bpo-28964: add line number of node (if available) to ast.literal_eval error messages (GH-23677)
https://github.com/python/cpython/commit/586f3dbe15139cafb2a6ffb82cea146906561844

Thank you!

On Fri, Dec 25, 2020 at 11:05 AM Batuhan Taskaya <report@bugs.python.org>
wrote:

>
> Change by Batuhan Taskaya <isidentical@gmail.com>:
>
>
> ----------
> resolution:  -> fixed
> stage: patch review -> resolved
> status: open -> closed
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue28964>
> _______________________________________
>