R. David Murray <rdmurray@bitdance.com> added the comment: Nope, a tuple display is not equal to a parenthesized list. For example, in: x = 1, 2, 3 1, 2, 3 is a tuple display. The parenthesis are optional in that case (in the general case it is the comma that makes the tuple, not the parens). However, as far as I can see that's the only mention of "tuple display" in the docs, which makes the doc you reference less than useful to a reader that doesn't know what it means. ---------- nosy: +r.david.murray title: Fix "tuple display" mention in Expressions -> Define "tuple display" in the docs _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33459> _______________________________________

Andrés Delfino <adelfino@gmail.com> added the comment: The thing is that "tuple displays" like: nums = (n for n in range(10)) Yield a generator expression instead of a tuple. Also, unparenthesized "tuple displays" like 1, 2, 3 can't be used in expressions, AFAIK:

...

...

if 3 == 1, 2, 3: SyntaxError: invalid syntax

So, you end up using parenthesized expressions (that may or may not shield tuples) to use tuples in expressions. So talking about "tuple expressions" in the operator precedence table doesn't make much sense to me :/ Also, if a "tuple display" doesn't yield a tuple, should it be named a "tuple display" after all? ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33459> _______________________________________

R. David Murray <rdmurray@bitdance.com> added the comment: That's a generator expression, just like [x for x in ramge(3)] is a list comprehension, not a list display. And yes, in a number of circumstances parenthesis are required to delimit the tuple display and disambiguate the syntax. That is, it is the 1, 2, 3 that is the tuple display, but sometimes you have to enclose it in parenthesis in order for the parser to recognize it. Which is why it would be good to give a more thorough explanation of what a tuple display is than the unlabeled one Cheryl pointed out. I'm not entirely sure what the exact rules are for when you get a syntax error without the parens, myself :) ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33459> _______________________________________

R. David Murray <rdmurray@bitdance.com> added the comment: Hmm. OK, I didn't think that's how we'd defined those terms, but then I don't actually work with the parser much myself :) However, generator expressions are clearly called out as a separate thing. All of the other display types get their own section, so I would think tuple display should too if it really is a syntax unit...but maybe it isn't. Also, I'm not clear on what 'binding' means in that table entry. I see now why you wanted to say "parenthesized expression", but as far as I can see the previous text is referring to it as an expression list in parenthesis form. That's a bit wordy, which may be why someone used tuple display there. Clearly there is some ambiguity here that it would be nice to resolve, considering this is part of the language spec, but frankly I'm not sure what to suggest. At that level I'm not sure how the "operator precedence" is actually "resolved"...I think it is more a matter of it being implicit in the parsing, but I'm not sure. Like I said, not my area of expertise. ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33459> _______________________________________

miss-islington <mariatta.wijaya+miss-islington@gmail.com> added the comment: New changeset dc269971091710563a0d730a0d4b084901826c15 by Miss Islington (bot) (Andre Delfino) in branch 'master': bpo-33459: Fix "tuple displays" term in Expressions.rst (GH-6760) https://github.com/python/cpython/commit/dc269971091710563a0d730a0d4b0849018... ---------- nosy: +miss-islington _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33459> _______________________________________

Change by miss-islington <mariatta.wijaya+miss-islington@gmail.com>: ---------- pull_requests: +15576 pull_request: https://github.com/python/cpython/pull/15940 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33459> _______________________________________

Stéphane Wirtel <stephane@wirtel.be> added the comment: New changeset 4d2babd99022bf43dc659d9fe5700c1fc13808c4 by Stéphane Wirtel (Miss Islington (bot)) in branch '3.8': bpo-33459: Fix "tuple displays" term in Expressions.rst (GH-6760) (GH-15940) https://github.com/python/cpython/commit/4d2babd99022bf43dc659d9fe5700c1fc13... ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33459> _______________________________________