In `_warnings.c`, in the C equivalent of `warnings.warn_explicit()`, if the module globals are given (and not None), the warning will attempt to get the source line for the issued warning. To do this, it needs the module's loader.
Previously, it would only look up `__loader__` in the module globals. In https://github.com/python/cpython/issues/86298 we want to defer to the `__spec__.loader` if available.
The first step on this journey is to check that `loader == __spec__.loader` and issue another warning if it is not. This commit does that.
Since this is a PoC, only manual testing for now.
```python
# /tmp/foo.py
import warnings
import bar
warnings.warn_explicit(
'warning!',
RuntimeWarning,
'bar.py', 2,
module='bar knee',
module_globals=bar.__dict__,
)
```
```python
# /tmp/bar.py
import sys
import os
import pathlib
# __loader__ = pathlib.Path()
```
Then running this: `./python.exe -Wdefault /tmp/foo.py`
Produces:
```
bar.py:2: RuntimeWarning: warning!
import os
```
Uncomment the `__loader__ = ` line in `bar.py` and try it again:
```
sys:1: ImportWarning: Module bar; __loader__ != __spec__.loader (<_frozen_importlib_external.SourceFileLoader object at 0x109f7dfa0> != PosixPath('.'))
bar.py:2: RuntimeWarning: warning!
import os
```
Automerge-Triggered-By: GH:warsaw
Support for bytes broke sometime between Python 3.2 and 3.6 and has been broken ever since. Trying to bring back supports is surprisingly difficult in the face of -b and checking for keys in sys.path_importer_cache. Since the support was broken for so long, trying to overcome the difficulty of bringing back the support has been deemed not worth it.
Co-authored-by: Eryk Sun <eryksun@gmail.com>
Co-authored-by: Brett Cannon <brett@python.org>
Broadened scope of the document to explicitly discuss and differentiate between ``__main__.py`` in packages versus the ``__name__ == '__main__'`` expression (and the idioms that surround it), as well as ``import __main__``.
Co-authored-by: Géry Ogam <gery.ogam@gmail.com>
Co-authored-by: Éric Araujo <merwok@netwok.org>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
@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
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>
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.
In a previous change, __spec__.parent was prioritized over
__package__. That is a backwards-compatibility break, but we do
eventually want __spec__ to be the ground truth for module details. So
this change reverts the change in semantics and instead raises an
ImportWarning when __package__ != __spec__.parent to give people time
to adjust to using spec objects.
not defined for a relative import.
This is the start of work to try and clean up import semantics to rely
more on a module's spec than on the myriad attributes that get set on
a module. Thanks to Rose Ames for the patch.
The concept of .pyo files no longer exists. Now .pyc files have an
optional `opt-` tag which specifies if any extra optimizations beyond
the peepholer were applied.
importlib.abc.Loader.exec_module() is also defined.
Before this change, create_module() was optional **and** could return
None to trigger default semantics. This change now reduces the
options for choosing default semantics to one and in the most
backporting-friendly way (define create_module() to return None).
Barry Warsaw
Hugo van Kemenade
Brett Cannon
Thomas Grainger
Ned Batchelder
slateny
David Gilbertson
Christian Clauss
Jack DeVries
Furkan Onder
Géry Ogam
Zackery Spytz
Bonifacio de Oliveira
Oleg Höfling
Shu
Joannah Nanjekye
Serhiy Storchaka
Andrés Delfino
Brett Cannon
Benjamin Peterson
kms70847
Dominik Miedziński
Mariatta
Marco Buttu
Eric Snow
Berker Peksag