open(), io.open(), codecs.open() and fileinput.FileInput no longer
accept "U" ("universal newline") in the file mode. This flag was
deprecated since Python 3.3.
* Always return bytes from _HackedGetData.get_data().
Ensure the imp.load_source shim always returns bytes by reopening the file in
binary mode if needed. Hash-based pycs have to receive the source code in bytes.
It's tempting to change imp.get_suffixes() to always return 'rb' as a mode, but
that breaks some stdlib tests and likely 3rdparty code, too.
Bug didn't manifest itself when importing a module with source as .py files are always the first on the search path. The issue only showed up in bytecode-only packages where the calculated file path would be ``__init__.py/__init__.pyc``.
Patch by Alexandru Ardelean.
To resolve a compatibility problem found with py2exe and
pywin32, imp.load_dynamic() once again ignores previously loaded modules
to support Python modules replacing themselves with extension modules.
Patch by Petr Viktorin.
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.
Along the way, dismantle importlib._bootstrap._SpecMethods as it was
no longer relevant and constructing the new function required
partially dismantling the class anyway.
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).
