bpo-41762: Fix usage of productionlist markup in the doc

[vstinner]

Use an unique identifier for the different grammars documented using
the Sphinx productionlist markup.

productionlist markups of the same grammar, like "expressions" or
"compound statements", use the same identifier.

https://bugs.python.org/issue41762

[vstinner]

I checked manually the rendered HTML documentation: reference/expressions.html still contains clickable links between the different grammar items. For example, I can click on "expression" from lambda_expr and I'm pointed to expression definition of the "6.13. Conditional expressions" section. I also checked library/string.html: links are kept.

cc @JulienPalard@deronnax@isidentical@pablogsal@lysnikolaou

[vstinner]

This change breaks the link to stmt_list.

Should we use the same identifier here, in expressions, simple statements and compound statements?

[pablogsal]

Yeah, I think that is a good idea (to preserve those links). Is there any other missing links between sections?

[pablogsal]

Or maybe use the least amount of namespaces possible?

[vstinner]

I didn't check all modified pages.

[corona10]

@vstinner@pablogsal

I can check my PR works well after this PR is merged :)
#22198

[vstinner]

Doc/reference/*.rst must all live in the same productionlist domain (same grammar):

• top_level => compound_stmts => simple_stmts => expressions => lexical_analysis

Examples:

• https://docs.python.org/dev/reference/toplevel_components.html#interactive-input : compound_stmt of interactive_input links to https://docs.python.org/dev/reference/compound_stmts.html#grammar-token-compound-stmt
• https://docs.python.org/dev/reference/compound_stmts.html#grammar-token-stmt-list : simple_stmt of stmt_list links to: https://docs.python.org/dev/reference/simple_stmts.html#grammar-token-simple-stmt
• https://docs.python.org/dev/reference/simple_stmts.html#grammar-token-expression-stmt : starred_expression of expression_stmt links to https://docs.python.org/dev/reference/expressions.html#grammar-token-starred-expression
• https://docs.python.org/dev/reference/expressions.html#grammar-token-atom : identifier of atom links to: https://docs.python.org/dev/reference/lexical_analysis.html#grammar-token-identifier

[vstinner]

Ok, I pushed a 3rd commit.

I checked links between reference/ documents and they all have been repaired by my 3rd commit.

I'm going to merge this PR once the CI pass.

[miss-islington]

Thanks @vstinner for the PR 🌮🎉.. I'm working now to backport this PR to: 3.8, 3.9.
🐍🍒⛏🤖

[miss-islington]

Sorry @vstinner, I had trouble checking out the 3.9 backport branch.
Please backport using cherry_picker on command line.
cherry_picker 8af239eacfcf52e4e0e2b0223e7cea4672309483 3.9

[bedevere-bot]

GH-22300 is a backport of this pull request to the 3.8 branch.

[miss-islington]

Thanks @vstinner for the PR 🌮🎉.. I'm working now to backport this PR to: 3.9.
🐍🍒⛏🤖

[bedevere-bot]

GH-22301 is a backport of this pull request to the 3.9 branch.