In some development setups it is inconvenient or impossible to write bytecode
caches to the code tree, but the bytecode caches are still useful. The
PYTHONPYCACHEPREFIX environment variable allows specifying an alternate
location for cached bytecode files, within which a directory tree mirroring the code
tree will be created. This cache tree is then used (for both reading and writing)
instead of the local `__pycache__` subdirectory within each source directory.
Exposed at runtime as sys.pycache_prefix (defaulting to None), and can
be set from the CLI as "-X pycache_prefix=path".
Patch by Carl Meyer.
Multi-phase initialized modules allow m_traverse to be called while the
module is still being initialized, so module authors may need to account
for that.
* Fix multiple typos in code comments
* Add spacing in comments (test_logging.py, test_math.py)
* Fix spaces at the beginning of comments in test_logging.py
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.
Previously AttributeError was raised, but that's not very reflective of the fact that the requested module can't be found since the specified parent isn't actually a package.
* bpo-29514: Check magic number for micro release
Add a dict importlib.util.EXPECTED_MAGIC_NUMBERS which
details the initial and expected pyc magic number for
each minor release. This gives a mechanism for users to
check if the magic number has changed within a release and
for a test to ensure procedure is followed if a change is
necessary.
Add a test to check the current MAGIC_NUMBER against the
expected number for the release if the current release is
at candidate or final level. On test failure, describe to
the developer the procedure for changing the magic number.
* Simplify magic number release test
Simplify the magic number release test by removing
EXPECTED_MAGIC_NUMBERS table and making the expected
magic number self-contained within the test.
BPO: 29514
* Improve magic number test execution and message
Improve the execution of the magic number test by
using skipUnless for alpha and beta releases, and
directly inheriting from unittest.TestCase rather than
using the machinery for the other tests. Also improve
the error message to explain the reason for caution in
changing the magic number.
BPO: 29514
Multi-phase extension module import now correctly allows the
``m_methods`` field to be used to add module level functions
to instances of non-module types returned from ``Py_create_mod``.
Patch by Xiang Zhang.
Windows.
Originally only b'PYTHONCASEOK' was being checked for in os.environ,
but that won't work under Windows where all environment variables are
strings (on OS X they are bytes).
Thanks to Eryk Sun for the bug report.
modules can't be lazily loaded.
Thanks to Python 3.6 allowing for types.ModuleType to have its
__class__ mutated, the restriction can be lifted by calling
create_module() on the wrapped loader.
* Rename libregrtest.main_in_temp_cwd() to libregrtest.main()
* Add regrtest.main_in_temp_cwd() alias to libregrtest.main()
* Move old main_in_temp_cwd() code into libregrtest.Regrtest.main()
* Update multiple scripts to call libregrtest.main()
importlib.util.LazyLoader.
The class was checking its argument as to whether its implementation
of create_module() came directly from importlib.abc.Loader. The
problem is that the classes coming from imoprtlib.machinery do not
directly inherit from the ABC as they come from _frozen_importlib.
Because the documentation has always said that create_module() was
ignored, the check has simply been removed.
with no known parent package.
Previously SystemError was raised if the parent package didn't exist
(e.g., __package__ was set to '').
Thanks to Florent Xicluna and Yongzhi Pan for reporting the issue.
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.
Known limitations of the current implementation:
- documentation changes are incomplete
- there's a reference leak I haven't tracked down yet
The leak is most visible by running:
./python -m test -R3:3 test_importlib
However, you can also see it by running:
./python -X showrefcount
Importing the array or _testmultiphase modules, and
then deleting them from both sys.modules and the local
namespace shows significant increases in the total
number of active references each cycle. By contrast,
with _testcapi (which continues to use single-phase
initialisation) the global refcounts stabilise after
a couple of cycles.
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).
Adds `load_package_tests` function to test.support, uses it in test_asyncio,
test_email, test_json, test_tools, test_importlib and all test_importlib
sub-packages to implement test discovery.
Along the way, dismantle importlib._bootstrap._SpecMethods as it was
no longer relevant and constructing the new function required
partially dismantling the class anyway.
old methods now provide implementations when PEP 451 APIs are present.
This should help with backwards-compatibility with code which has not
been updated to work with PEP 451.
module loaders.
Due to the fact that the call signatures for extension modules and
built-in modules does not allow for the specifying of what module to
initialize and that on Windows all extension modules are built-in
modules, work to clean up built-in and extension module initialization
will have to wait until Python 3.5. Because of this the semantics of
exec_module() would be incorrect, so removing the methods for now is
the best option; load_module() is still used as a fallback by
importlib and so this won't affect semantics.
and stop importlib.machinery.FileFinder treating '' as '.'.
Previous PathFinder transformed '' into '.' which led to __file__ for
modules imported from the cwd to always be relative paths. This meant
the values of the attribute were wrong as soon as the cwd changed.
This change now means that as long as the site module is run (which
makes all entries in sys.path absolute) then all values for __file__
will also be absolute unless it's for __main__ when specified by file
path in a relative way (modules imported by runpy will have an
absolute path).
Now that PathFinder is no longer treating '' as '.' it only makes
sense for FileFinder to stop doing so as well. Now no transformation
is performed for the directory given to the __init__ method.
Thanks to Madison May for the initial patch.
This commit fixes a regression that sneaked into Python 3.3 where importlib
was not respecting -E when checking for the PYTHONCASEOK environment variable.
This commit fixes a regression that sneaked into Python 3.3 where importlib
was not respecting -E when checking for the PYTHONCASEOK environment variable.
The helper function makes it easier to implement
imoprtlib.abc.InspectLoader.get_source() by making that function
require just the raw bytes for source code and handling all other
details.
To make sure there is no issue with code that is both Python 2 and 3
compatible, there are no plans to remove the module any sooner than
Python 4 (unless the community moves to Python 3 solidly before then).
Ned Deily
Carl Meyer
Barry Warsaw
Marcel Plch
Victor Stinner
Brett Cannon
Serhiy Storchaka
Victor Stinner
Mike
Benjamin Peterson
Antoine Pitrou
Ville Skyttä
Milan Oberkirch
Garvit Khatri
Eric Appelt
Matthias Bussonnier
Xavier de Gaye
Eric Snow
Brett Cannon
Raymond Hettinger
Nick Coghlan
Berker Peksag
Steve Dower
Zachary Ware
Meador Inge