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.
* 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
Co-authored-by: Brian Skinn <brian.skinn@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.
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>
* 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.
- 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.
Co-authored-by: Emma Smith <emma@emmatyping.dev>
Co-authored-by: Carol Willing <carolcode@willingconsulting.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.
Add glossary entry for `token`, and link to it.
Avoid talking about tokens in the SyntaxError intro (errors.rst); at this point
tokenization is too much of a technical detail. (Even to an advanced reader,
the fact that a *single* token is highlighted isn't too relevant. Also, we don't
need to guarantee that it's a single token.)
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
As a first step toward aligning the grammar documentation with Python's actual
grammar, this overrides the ReST `productionlist` directive to:
- use `:` instead of the `::=` symbol
- add syntax highlighting for strings (using a Pygments highlighting class)
All links and link targets should be preserved. (Unfortunately, this reaches
into some Sphinx internals; I don't see a better way to do exactly what
Sphinx does.)
This also adds a new directive, `grammar-snippet`, which formats the snippet
almost exactly like what's in the source, modulo syntax highlighting and
keeping the backtick character to mark links to other rules.
This will allow formatting the snippets as in the grammar file
(file:///home/encukou/dev/cpython/Doc/build/html/reference/grammar.html).
The new directive is applied to two simple rules in toplevel_components.rst
---------
Co-authored-by: Blaise Pabon <blaise@gmail.com>
Co-authored-by: William Ferreira <wqferr@gmail.com>
Co-authored-by: bswck <bartoszpiotrslawecki@gmail.com>
Co-authored-by: Adam Turner <9087854+aa-turner@users.noreply.github.com>
Ignore PermissionError when checking cwd during import
On macOS `getcwd(3)` can return EACCES if a path component isn't readable,
resulting in PermissionError. `PathFinder.find_spec()` now catches these and
ignores them - the same treatment as a missing/deleted cwd.
Introduces `test.support.os_helper.save_mode(path, ...)`, a context manager
that restores the mode of a path on exit.
This is allows finer control of exception handling and robust environment
restoration across platforms in `FinderTests.test_permission_error_cwd()`.
Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>
Co-authored-by: Brett Cannon <brett@python.org>
"Generally, mixed-mode arithmetic combining real and complex variables should
be performed directly, not by first coercing the real to complex, lest the sign
of zero be rendered uninformative; the same goes for combinations of pure
imaginary quantities with complex variables." (c) Kahan, W: Branch cuts for
complex elementary functions.
This patch implements mixed-mode arithmetic rules, combining real and
complex variables as specified by C standards since C99 (in particular,
there is no special version for the true division with real lhs
operand). Most C compilers implementing C99+ Annex G have only these
special rules (without support for imaginary type, which is going to be
deprecated in C2y).
* Removes erroneous explanation of the `global` statement restrictions; a name declared as global can be subsequently bound using any kind of name binding operation.
* Updates `test_global.py` to also test various name-binding scenarios for global
variables to ensure correct behavior
* add test for the predefined object's attributes
* Include the "object" type in the lists of documented types
* remove 'or' from augment tuple
* 📜🤖 Added by blurb_it.
* Add cross-reference to news
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
* Fix format for the function parameter
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
* Add space
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
* add reference for the 'object'
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
* add reference for NotImplemented
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
* Change ref:`string <textseq>` as class:`str`
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
* remove hyphen from `newly-created`
* Update Doc/reference/datamodel.rst
'dictionaries' to 'dict'
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
* Update predefined attribute types in testPredefinedAttrs
* Change `universal type` as `top type`
* Don't mention about the top type
* Update the description of richcmpfuncs
* Update Doc/library/stdtypes.rst
Co-authored-by: Éric <merwok@netwok.org>
* Revert: Hierarchy Section in Data Model Documentation
* Revert to original explanations of __new__ and __init__ methods in datamodel.rst for improved clarity.
* Update Doc/reference/datamodel.rst
Co-authored-by: Éric <merwok@netwok.org>
* Remove blank line
Co-authored-by: Éric <merwok@netwok.org>
* Use ref:`str <textseq>` instead of :class:`str
Co-authored-by: Éric <merwok@netwok.org>
* Revert changes the description of Other Built-in Types in stdtypes.rst
* Update Doc/reference/datamodel.rst
Co-authored-by: Éric <merwok@netwok.org>
---------
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
Co-authored-by: Éric <merwok@netwok.org>
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
* Qualifying that the right operand's type must be a *strict* subclass for the reflected method to take precedence avoids an edge case / counter-example when the types are actually equal.
Co-authored-by: Ethan Furman <ethan@stoneleaf.us>
The term "free variable" has unfortunately become genuinely
ambiguous over the years (presumably due to the names of
some relevant code object instance attributes).
While we can't eliminate that ambiguity at this late date, we can
at least alert people to the potential ambiguity by describing
both the formal meaning of the term and the common
alternative use as a direct synonym for "closure variable".
---------
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
* Setting the __module__ attribute for a class now removes the
__firstlineno__ item from the type's dict.
* The _collections_abc and _pydecimal modules now completely replace the
collections.abc and decimal modules after importing them. This
allows to get the source of classes and functions defined in these
modules.
* inspect.findsource() now checks whether the first line number for a
class is out of bound.
To recap: the objective is to make starred expressions valid in `subscription`,
which is used for generics: `Generic[...]`, `list[...]`, etc.
What _is_ gramatically valid in such contexts? Seemingly any of the following.
(At least, none of the following throw `SyntaxError` in a 3.12.3 REPL.)
Generic[x]
Generic[*x]
Generic[*x, y]
Generic[y, *x]
Generic[x := 1]
Generic[x := 1, y := 2]
So introducting
flexible_expression: expression | assignment_expression | starred_item
end then switching `subscription` to use `flexible_expression` sorts that.
But then we need to field `yield` - for which any of the following are
apparently valid:
yield x
yield x,
yield x, y
yield *x,
yield *x, *y
Introducing a separate `yield_list` is the simplest way I've been figure out to
do this - separating out the special case of `starred_item ,`.
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Using a standard library class makes this test difficult to maintain
as other tests and other parts of the stdlib may create subclasses,
which may still be alive when this test runs depending on GC timing.
Closes#123242. The real criterion is that the attribute does not
exist on heap types, but I don't think we should discuss heap vs.
static types in the language reference.
Jelle Zijlstra