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>
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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
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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>
Petr Viktorin