Author mbussonn
Recipients Mark.Shannon, benjamin.peterson, eitan.adler, flherne, georg.brandl, inada.naoki, lukasz.langa, mbussonn, minrk, ncoghlan, ned.deily, rhettinger, serhiy.storchaka, vstinner
Date 2018-05-25.15:45:50
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <1527263150.35.0.682650639539.issue32911@psf.upfronthosting.co.za>
In-reply-to
Content
Łukasz Langa wrote:

> Inadasan, I think what we should do is to amend `ast.parse()` and `compile()` docs that mode="exec" treats given code as a module, we should even give the docstring handling as an example.

That is what I proposed in https://bugs.python.org/issue33477
and in PR https://github.com/python/cpython/pull/6973

The other surprise, is that even is I  knew AST were change and had a docstring field I was not expecting `compile()` to be affected.


I think that the change for ast to have a docstring field is a good one from an API point of view for ast nodes. But It should probably be opt-in, at least with a deprecation period to make it the default. The other issue is that as it affect only sequence of statement where the first node is (was) a string, it can lead to really subtle difference in execution. 



MinRk said:
> The only affected case for us is interactively typed string literals in single statement cells not displaying themselves as results

It might affect our downstream consumers that have syntax/ast transformation like sage, sympy on top of IPython. I doubt we have any but it's a possibility. 

While I would prefer (B) as well, I see how the new behavior can be useful in some case, and strongly also support the addition of a `multiline` mode, which correspond to what 3.6 and before were doing with `exec`. The other possibility is to leave `exec` and `ast.parse` with 3.6 behavior, and include a `'module'` mode that does reflect current 3.7 behavior.
History
Date User Action Args
2018-05-25 15:45:50mbussonnsetrecipients: + mbussonn, georg.brandl, rhettinger, ncoghlan, vstinner, benjamin.peterson, ned.deily, inada.naoki, lukasz.langa, Mark.Shannon, serhiy.storchaka, eitan.adler, minrk, flherne
2018-05-25 15:45:50mbussonnsetmessageid: <1527263150.35.0.682650639539.issue32911@psf.upfronthosting.co.za>
2018-05-25 15:45:50mbussonnlinkissue32911 messages
2018-05-25 15:45:50mbussonncreate