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author | Brett Cannon <brett@python.org> | 2013-06-12 20:59:46 (GMT) |
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committer | Brett Cannon <brett@python.org> | 2013-06-12 20:59:46 (GMT) |
commit | b1611e2772af2c6eb73a6b3d04b3dbb43308fa6c (patch) | |
tree | 7cd26cc5f09f341a69572c40f16638053ae86d08 /Lib/importlib | |
parent | 638ce0779b4dceea39c2f77346aeab9824e48548 (diff) | |
download | cpython-b1611e2772af2c6eb73a6b3d04b3dbb43308fa6c.zip cpython-b1611e2772af2c6eb73a6b3d04b3dbb43308fa6c.tar.gz cpython-b1611e2772af2c6eb73a6b3d04b3dbb43308fa6c.tar.bz2 |
Issue #15767: Introduce ModuleNotFoundError, a subclass of
ImportError.
The exception is raised by import when a module could not be found.
Technically this is defined as no viable loader could be found for the
specified module. This includes ``from ... import`` statements so that
the module usage is consistent for all situations where import
couldn't find what was requested.
This should allow for the common idiom of::
try:
import something
except ImportError:
pass
to be updated to using ModuleNotFoundError and not accidentally mask
ImportError messages that should propagate (e.g. issues with a
loader).
This work was driven by the fact that the ``from ... import``
statement needed to be able to tell the difference between an
ImportError that simply couldn't find a module (and thus silence the
exception so that ceval can raise it) and an ImportError that
represented an actual problem.
Diffstat (limited to 'Lib/importlib')
-rw-r--r-- | Lib/importlib/_bootstrap.py | 15 |
1 files changed, 4 insertions, 11 deletions
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index e477b55..cd41336 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -1553,11 +1553,7 @@ def _find_and_load_unlocked(name, import_): raise ImportError(msg, name=name) loader = _find_module(name, path) if loader is None: - exc = ImportError(_ERR_MSG.format(name), name=name) - # TODO(brett): switch to a proper ModuleNotFound exception in Python - # 3.4. - exc._not_found = True - raise exc + raise ModuleNotFoundError(_ERR_MSG.format(name), name=name) elif name not in sys.modules: # The parent import may have already imported this module. loader.load_module(name) @@ -1643,15 +1639,12 @@ def _handle_fromlist(module, fromlist, import_): from_name = '{}.{}'.format(module.__name__, x) try: _call_with_frames_removed(import_, from_name) - except ImportError as exc: + except ModuleNotFoundError as exc: # Backwards-compatibility dictates we ignore failed # imports triggered by fromlist for modules that don't # exist. - # TODO(brett): In Python 3.4, have import raise - # ModuleNotFound and catch that. - if getattr(exc, '_not_found', False): - if exc.name == from_name: - continue + if exc.name == from_name: + continue raise return module |