Update documentation section for "Future statements" to reflect that `from __future__ import annotations` is on by default, and no features require using the future statement now.
This is a first edition, ready to go out with the implementation. We'll iterate during the rest of the period leading up to 3.10.0.
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
Co-authored-by: Fidget-Spinner <28750310+Fidget-Spinner@users.noreply.github.com>
Co-authored-by: Brandt Bucher <brandt@python.org>
Co-authored-by: Raymond Hettinger <1623689+rhettinger@users.noreply.github.com>
Co-authored-by: Guido van Rossum <guido@python.org>
In Python 2, it was possible to use `except` with a nested tuple, and occasionally natural. For example, `zope.formlib.interfaces.InputErrors` is a tuple of several exception classes, and one might reasonably think to do something like this:
try:
self.getInputValue()
return True
except (InputErrors, SomethingElse):
return False
As of Python 3.0, this raises `TypeError: catching classes that do not inherit from BaseException is not allowed` instead: one must instead either break it up into multiple `except` clauses or flatten the tuple. However, the reference documentation was never updated to match this new restriction. Make it clear that the definition is no longer recursive.
Automerge-Triggered-By: GH:ericvsmith
Follow up to 7cdf30fff3 and 4173320920. This addresses the point "1. Update links in typing, subscription and union to point to GenericAlias." in the bpo for this PR.
@ericsnowcurrently This PR will change the following:
In the library documentation importlib.rst:
- `module.__package__` can be `module.__name__` for packages;
- `spec.parent` can be `spec.__name__` for packages;
- `spec.loader` is not `None` for namespaces packages.
In the language documentation import.rst:
- `spec.loader` is not `None` for namespace packages.
Automerge-Triggered-By: GH:warsaw
This is a trivial fix to [bpo-39416](), which didn't come up until it was already committed
```
Change "Numeric" to "numeric".
I believe this is trivial enough to not need an issue or a NEWS entry, although
I'm unclear on what branches the original pull request received backports.
```
Automerge-Triggered-By: GH:merwok
[bpo-39416](): Document string representations of the Numeric classes
This is a change to the specification of the Python language.
The idea here is to put sane minimal limits on the Python language's default
representations of its Numeric classes. That way "Marty's Robotic Massage Parlor
and Python Interpreter" implementation of Python won't do anything too
crazy.
Some discussion in the email thread:
Subject: Documenting Python's float.__str__()
https://mail.python.org/archives/list/python-dev@python.org/thread/FV22TKT3S2Q3P7PNN6MCXI6IX3HRRNAL/
The hard part was making all the tests pass; there are some subtle issues here, because apparently the future import wasn't tested very thoroughly in previous Python versions.
For example, `inspect.signature()` returned type objects normally (except for forward references), but strings with the future import. We changed it to try and return type objects by calling `typing.get_type_hints()`, but fall back on returning strings if that function fails (which it may do if there are future references in the annotations that require passing in a specific namespace to resolve).
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 "python-grammar".
Sphinx 3 disallows having more than one productionlist markup with
the same name. Simply remove names in this case, since names are not
shown anyway. For example, fix the Sphinx 3 warning:
Doc/reference/introduction.rst:96: duplicate token description
of *:name, other instance in reference/expressions
Sphinx 3 requires to refer to terms with the exact case.
For example, fix the Sphinx 3 warning:
Doc/library/pkgutil.rst:71: WARNING: term Loader not found in case
sensitive match.made a reference to loader instead.
* Reorder the __aenter__ and __aexit__ checks for async with
* Add assertions for async with body being skipped
* Swap __aexit__ and __aenter__ loading in the documentation
* __enter__ is now looked up before __exit__ to give a more intuitive error message
* add pseudo-code equivalent for the with statement
* fix pseudo-code for the async with statement to use a finally clause
* use SUITE rather than BLOCK for consistency with the language grammar
Patch by Géry Ogam.
The importlib.metadata documentation uses hardcoded links to internal
pages. This results in minor rendering issues. This change replaces
the hardcoded links with suitable Sphinx roles.
Signed-off-by: Oleg Höfling <oleg.hoefling@gmail.com>
DeprecationWarning will continue to be emitted for invalid escape
sequences in string and bytes literals just as it did in 3.7.
SyntaxWarning may be emitted in the future. But per mailing list
discussion, we don't yet know when because we haven't settled on how to
do so in a non-disruptive manner.
(Applies 4c5b6bac24 to the master branch).
(This is https://github.com/python/cpython/pull/15142 for master/3.9)
https://bugs.python.org/issue32912
Automerge-Triggered-By: @gpshead
* bpo-36540: Documentation for PEP570 - Python positional only arguments
* fixup! bpo-36540: Documentation for PEP570 - Python positional only arguments
* Update reference for compound statements
* Apply suggestions from Carol
Co-Authored-By: Carol Willing <carolcode@willingconsulting.com>
* Update Doc/tutorial/controlflow.rst
Co-Authored-By: Carol Willing <carolcode@willingconsulting.com>
* Add extra bullet point and minor edits
Prefer the full wording instead, as it is more meaningful for someone not familiar with the terms.
Also, LFS/RHS is not used anywhere else in the documentation, while left/right-hand side mentions are common.
Methods are always bound, and `__self__` can no longer be `NULL`
(`method_new()` and `PyMethod_New()` both explicitly check for this).
Moreover, once a bound method is bound, it *stays* bound and won't be re-bound
to something else, so the section in the datamodel that talks about accessing
an methods in a different descriptor-binding context doesn't apply any more in
Python 3.
The documentation was not covering multiple targets enclosed by
parenthesis nor multiple targets enclosed by brackets, adding them all
would be heavy, an else cover them all and is lighter to read.
Fix a bug I introduced in #9864 by which coroutines are treated as synonymous of function coroutines.
Also, fix the same mistake (coroutines == function coroutines) already present in other parts of the reference.
I'm very sorry for the hassle.
When `__getattr__` is implemented, attribute lookup will always fall back to that,
even if the initial failure comes from `__getattribute__` or a descriptor's `__get__`
method (including property methods).
The f-string example for using datetime format specifier does not match the given output.
Changed the format from %b to %B so it matches the output of "January".
Make it clear that setting __class__ on a module has worked since 3.5,
but support for __getattr__ and __dir__ on module instances requires 3.7+
Patch by Cheryl Sabella.
* Document `from __future__ import annotations`
* Provide plumbing and tests for `from __future__ import annotations`
* Implement unparsing the AST back to string form
This is required for PEP 563 and as such only implements a part of the
unparsing process that covers expressions.
In lexical analysis reference documentation, the internal link to
the string literal concatenation section was written as`.. _string-catenation:`.
Changed that to `.. _string-concatenation:`.
Python now supports checking bytecode cache up-to-dateness with a hash of the
source contents rather than volatile source metadata. See the PEP for details.
While a fairly straightforward idea, quite a lot of code had to be modified due
to the pervasiveness of pyc implementation details in the codebase. Changes in
this commit include:
- The core changes to importlib to understand how to read, validate, and
regenerate hash-based pycs.
- Support for generating hash-based pycs in py_compile and compileall.
- Modifications to our siphash implementation to support passing a custom
key. We then expose it to importlib through _imp.
- Updates to all places in the interpreter, standard library, and tests that
manually generate or parse pyc files to grok the new format.
- Support in the interpreter command line code for long options like
--check-hash-based-pycs.
- Tests and documentation for all of the above.
The current behaviour of yield expressions inside comprehensions and
generator expressions is essentially an accident of implementation - it
arises implicitly from the way the compiler handles yield expressions inside
nested functions and generators.
Since the current behaviour wasn't deliberately designed, and is inherently
confusing, we're deprecating it, with no current plans to reintroduce it.
Instead, our advice will be to use a named nested generator definition
for cases where this behaviour is desired.
async and await keywords has been merged into upstream, but they are
all missing in the lexical analysis docs. This change adds them to the
appropriate keywords section in documentation.
f_trace_lines: enable/disable line trace events
f_trace_opcodes: enable/disable opcode trace events
These are intended primarily for testing of the interpreter
itself, as they make it much easier to emulate signals
arriving at unfortunate times.
The data model section of the language reference was written well
before the zero-argument form of super() was added.
To avoid giving the impression that they're doing something
unusual, this updates the description of `__new__` and `__init__`
to use the zero-argument form.
Patch by Cheryl Sabella.
Builtin container types have two potential link targets in the docs:
- their entry in the list of builtin callables
- their type documentation
This change brings `bytes` and `bytearray` into line with other
container types by having cross-references default to linking to
their type documentation, rather than their builtin callable entry.