The behaviour of Cut in nested parentheses, Repeat, Opt, and similar
is somewhat chaotic. Apparently even the academic papers on PEG aren't
as clear as they could be.
And it doesn't really matter. Python only uses top-level cuts.
When that changes, we can clarify as much as necessary (and even
change the implementation to make sense for what we'll need).
Document that this is deliberately unspecified, and add a test to
make sure any decision is deliberate, tested and documented.
(cherry picked from commit f0a0467c176e245a8fd45d4480a0876d748d7e78)
Co-authored-by: Petr Viktorin <encukou@gmail.com>
gh-69686: Remove untrue part of `__import__` replacement docs (GH-143261)
Remove untrue part of `__import__` replacement docs
The original statement effectively says that replacing `__import__` at global scope affects import statements, and not only that, but only import statements within the rest of the executing module. None of that has been true since at least Python 2.7, I think.
This was likely missed in python/cpython#69686.
(cherry picked from commit 79c03ac0015ccf1cbb759f870e2af9d68f60fe3a)
Co-authored-by: Thanos <111999343+Sachaa-Thanasius@users.noreply.github.com>
gh-101100: Fix references to the set methods (GH-141857)
(cherry picked from commit 1d8f3ed2eba762e60a02ff87e782a5c7dcd0e77c)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Much of the information was duplicated in stdtypes.rst; this PR keeps
lexical/syntactical details in Lexical Analysis and the evaluation & runtime
behaviour in Standard types, with cross-references between the two.
Since the t-string section only listed differences from f-strings, and the
grammar for the two is equivalent, that section was moved to Standard types
almost entirely.
(cherry picked from commit aea5531583aaa8bfdf3ebca914e9c694617c3489)
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Blaise Pabon <blaise@gmail.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
This simplifies the Lexical Analysis section on Names (but keeps it technically correct) by putting all the info about non-ASCII characters in a separate (and very technical) section.
It uses a mental model where the parser doesn't handle Unicode complexity “immediately”, but:
- parses any non-ASCII character (outside strings/comments) as part of a name, since these can't (yet) be e.g. operators
- normalizes the name
- validates the name, using the xid_start/xid_continue sets
(cherry picked from commit 2ff8608b4da33f667960e5099a1a442197acaea4)
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Blaise Pabon <blaise@gmail.com>
Co-authored-by: Micha Albert <info@micha.zone>
Co-authored-by: KeithTheEE <kmurrayis@gmail.com>
gh-135944: Add a "Runtime Components" Section to the Execution Model Docs (gh-135945)
The section provides a brief overview of the Python runtime's execution environment. It is meant to be implementation agnostic,
(cherry picked from commit 46a1f0a9ff6e7cbea111dcb35e7aced1a7a3f3dc)
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
gh-135629: rewrite language reference section on except* to improve clarity (GH-136150)
(cherry picked from commit a651ec95241c25161d525499a739f01bfe527895)
Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
(cherry picked from commit 9f05f98730bbc36f4ad173845458827c4df879f6)
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Brian Schubert <brianm.schubert@gmail.com>
Make sure the ``:keyword:`` role works for ``case`` (GH-138878)
(cherry picked from commit 848d926786f19d2db95b352650df2b1702f4af65)
Co-authored-by: sobolevn <mail@sobolevn.me>
* GH-101100: Remove some entries from ``nitpick_ignore`` (GH-138464)
(cherry picked from commit 22cb9ba8f90bfbc0b8831365b6864f41b19d0b6e)
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
* Update check-warnings.py
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Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: James Parrott <80779630+JamesParrott@users.noreply.github.com>
Co-authored-by: Brian Schubert <brianm.schubert@gmail.com>
Co-authored-by: Adam Turner <9087854+aa-turner@users.noreply.github.com>
gh-132661: PEP 750 documentation: second pass (GH-137020)
(cherry picked from commit 4dae9b1ff16feae03bddb57ec3be5c42de14b1d2)
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Dave Peck <davepeck@gmail.com>
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Loïc Simon <loic.pano@gmail.com>
Co-authored-by: pauleveritt <pauleveritt@me.com>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
gh-135110: Fix misleading `generator.close()` documentation (GH-135152)
The documentation incorrectly stated that generator.close() 'raises' a
GeneratorExit exception. This was misleading because the method doesn't
raise the exception to the caller - it sends the exception internally
to the generator and returns None.
(cherry picked from commit 0d76dccc3b4376ba075a1737f58809e3d83aaaa3)
Co-authored-by: Connor Denihan <188690869+cdenihan@users.noreply.github.com>
Docs: Add cross-reference for `positional_item` in the `calls` productionlist (GH-129977)
Add missing hyperlink for `positional_item`
(cherry picked from commit d2154912b3b10823c138e904e74f2a1e7e7ca96c)
Co-authored-by: HarryLHW <123lhw321@gmail.com>
gh-135171: Update documentation for the generator expression (GH-135351)
* gh-135171: Update documentation for the generator expression
Document that the iterator for the leftmost "for" clause is created
immediately.
* Update Doc/reference/expressions.rst
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(cherry picked from commit 8979d3afe376c67931665070a79f6939ebcd940b)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Brian Skinn <brian.skinn@gmail.com>
Prepare the docs for using the notation used in the `python.gram`
file. If we want to sync the two, the meta-syntax should be the same.
Link the Full Grammar docs here; keep only a few extras.
Also, remove the distinction between lexical and syntactic rules,
except for whitespace handling.
With f- and t-strings, the line between the two is blurry.
(cherry picked from commit 28d91d06f13ceda3df0cefacec497c370eff4802)
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Blaise Pabon <blaise@gmail.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
Co-authored-by: Colin Marquardt <cmarqu42@gmail.com>
gh-134675: Add t-string prefixes to tokenizer module, lexical analysis doc, and add a test to make sure we catch this error in the future. (GH-134734)
* Add t-string prefixes to _all_string_prefixes, and add a test to make sure we catch this error in the future.
* Update lexical analysis docs for t-string prefixes.
(cherry picked from commit 08c78e02fab4a1c9c075637422d621f9c740959a)
Co-authored-by: Eric V. Smith <ericvsmith@users.noreply.github.com>
gh-119180: Updates to PEP 649/749 docs (GH-134640)
- Mention (again) that `type.__annotations__` is unsafe. It is now safe
when using only classes defined under PEP 649 semantics, but not with
classes defined using `from __future__ import annotations`.
- Mention that annotations on instances no longer work. There was already
an issue about this.
- Mention the general changes in the "Porting to Python 3.14" section.
- `annotationlib` was proposed by PEP-749, not PEP-649.
(cherry picked from commit 7291eaba8b20b19e7971d43d88286d5820e5eb56)
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Emma Smith <emma@emmatyping.dev>
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
gh-119180: More documentation for PEP 649/749 (GH-133552)
The SC asked that the Appendix in PEP-749 be added to the docs.
(cherry picked from commit 3396df56d0849e5154cb7d7d1c525df834bbe15e)
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
gh-127833: Add links to token types to the lexical analysis intro (GH-131468)
(cherry picked from commit 45bb5ba61a8d6dcaa44312b67fe6bade5e2ad992)
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
gh-127833: lexical analysis: Add backticks to BOM example (GH-132407)
(cherry picked from commit 0552ce0fb24d33b51fdd02a589ede95aabc0d8b5)
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
As noted on the issue, making get_annotate_function() support both types and
mappings is problematic because one object may be both. So let's add a new one
that works with any mapping.
This leaves get_annotate_function() not very useful, so remove it.
