module.

Patch by Berker Peksag.

unittest.TestCase in prep of running tests under frozen and source
importlib.

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).

importlib.abc.Loader.init_module_attrs() and implement
importlib.abc.InspectLoader.load_module().

The importlib.abc.Loader.init_module_attrs() method sets the various
attributes on the module being loaded. It is done unconditionally to
support reloading. Typically people used
importlib.util.module_for_loader, but since that's a decorator there
was no way to override it's actions, so init_module_attrs() came into
existence to allow for overriding. This is also why module_for_loader
is now pending deprecation (having its other use replaced by
importlib.util.module_to_load).

All of this allowed for importlib.abc.InspectLoader.load_module() to
be implemented. At this point you can now implement a loader with
nothing more than get_code() (which only requires get_source();
package support requires is_package()). Thanks to init_module_attrs()
the implementation of load_module() is basically a context manager
containing 2 methods calls, a call to exec(), and a return statement.

This should make the Linux distros happy as it is now easier to leave
importlib's tests out of their base Python distribution.

importlib.abc.FileLoader.load_module()/get_filename() and
importlib.machinery.ExtensionFileLoader.load_module() have their
single argument be optional as the loader's constructor has all the
ncessary information.

This allows for the deprecation of
imp.load_source()/load_compile()/load_package().

This time also recreating the Python/importlib.h file to make
make happy. See the ticket for details.

the buildbots to fail.

importlib.machinery.(FileFinder, SourceFileLoader,
_SourcelessFileLoader, ExtensionFileLoader).

This exposes all of importlib's mechanisms that will become public on
the sys module.

importlib._bootstrap is now frozen into Python/importlib.h and stored
as _frozen_importlib in sys.modules. Py_Initialize() loads the frozen
code along with sys and imp and then uses _frozen_importlib._install()
to set builtins.__import__() w/ _frozen_importlib.__import__().

attributes.

Issue #11235: Fix OverflowError when trying to import a source file whose modification time doesn't fit in a 32-bit timestamp.

code, to avoid timestamp collisions (especially on filesystems with a low
timestamp resolution) when checking for freshness of the bytecode.

imports with an empty string in sys.path.

This required moving the class from importlib/abc.py into
importlib/_bootstrap.py and jiggering some code to work better with the class.
This included changing how the file finder worked to better meet import
semantics. This also led to fixing importlib to handle the empty string from
sys.path as import currently does (and making me wish we didn't support that
instead just required people to insert '.' instead to represent cwd).

It also required making the new set_data abstractmethod create
any needed subdirectories implicitly thanks to __pycache__ (it was either this
or grow the SourceLoader ABC to gain an 'exists' method and either a mkdir
method or have set_data with no data arg mean to create a directory).

Lastly, as an optimization the file loaders cache the file path where the
finder found something to use for loading (this is thanks to having a
sourceless loader separate from the source loader to simplify the code and
cut out stat calls).
Unfortunately test_runpy assumed a loader would always work for a module, even
if you changed from underneath it what it was expected to work with. By simply
dropping the previous loader in test_runpy so the proper loader can be returned
by the finder fixed the failure.

At this point importlib deviates from import on two points:

1. The exception raised when trying to import a file is different (import does
an explicit file check to print a special message, importlib just says the path
cannot be imported as if it was just some module name).

2. the co_filename on a code object is not being set to where bytecode was
actually loaded from instead of where the marshalled code object originally
came from (a solution for this has already been agreed upon on python-dev but has
not been implemented yet; issue8611).

This required moving the class from importlib/abc.py into
importlib/_bootstrap.py and jiggering some code to work better with the class.
This included changing how the file finder worked to better meet import
semantics. This also led to fixing importlib to handle the empty string from
sys.path as import currently does (and making me wish we didn't support that
instead just required people to insert '.' instead to represent cwd).

It also required making the new set_data abstractmethod create
any needed subdirectories implicitly thanks to __pycache__ (it was either this
or grow the SourceLoader ABC to gain an 'exists' method and either a mkdir
method or have set_data with no data arg mean to create a directory).

Lastly, as an optimization the file loaders cache the file path where the
finder found something to use for loading (this is thanks to having a
sourceless loader separate from the source loader to simplify the code and
cut out stat calls).
Unfortunately test_runpy assumed a loader would always work for a module, even
if you changed from underneath it what it was expected to work with. By simply
dropping the previous loader in test_runpy so the proper loader can be returned
by the finder fixed the failure.

At this point importlib deviates from import on two points:

1. The exception raised when trying to import a file is different (import does
an explicit file check to print a special message, importlib just says the path
cannot be imported as if it was just some module name).

2. the co_filename on a code object is not being set to where bytecode was
actually loaded from instead of where the marshalled code object originally
came from (a solution for this has already been agreed upon on python-dev but has
not been implemented yet; issue8611).

svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r78242 | brett.cannon | 2010-02-19 11:01:06 -0500 (Fri, 19 Feb 2010) | 5 lines

  Importlib was not matching import's handling of .pyc files where it had less
  then 8 bytes total in the file.

  Fixes issues 7361 & 7875.
........

then 8 bytes total in the file.

Fixes issues 7361 & 7875.

svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r76146 | brett.cannon | 2009-11-07 15:55:05 -0800 (Sat, 07 Nov 2009) | 6 lines

  When trying to write new bytecode, importlib was not catching the IOError
  thrown if the file happened to be read-only to keep the failure silent.

  Fixes issue #7187. Thanks, Dave Malcolm for the report and analysis of the
  problem.
........

thrown if the file happened to be read-only to keep the failure silent.

Fixes issue #7187. Thanks, Dave Malcolm for the report and analysis of the
problem.

Obviously one shouldn't do whole sale conversions like this, but I was already
going through the test code and I was bored at the airport.

svn+ssh://svn.python.org/python/branches/py3k

........
  r73715 | benjamin.peterson | 2009-07-01 01:06:06 +0200 (Mi, 01 Jul 2009) | 1 line

  convert old fail* assertions to assert*
........