Close #20839: pkgutil.find_loader now uses importlib.util.find_spec

This commit is contained in:
Nick Coghlan 2014-03-04 20:39:42 +10:00
parent c913a7a6f6
commit dc855b7b1f
4 changed files with 37 additions and 20 deletions

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@ -74,15 +74,17 @@ support.
Retrieve a :pep:`302` module loader for the given *fullname*.
This is a convenience wrapper around :func:`importlib.find_loader` that
sets the *path* argument correctly when searching for submodules, and
also ensures parent packages (if any) are imported before searching for
submodules.
This is a backwards compatibility wrapper around
:func:`importlib.util.find_spec` that converts most failures to
:exc:`ImportError` and only returns the loader rather than the full
:class:`ModuleSpec`.
.. versionchanged:: 3.3
Updated to be based directly on :mod:`importlib` rather than relying
on the package internal PEP 302 import emulation.
.. versionchanged:: 3.4
Updated to be based on :pep:`451`
.. function:: get_importer(path_item)
@ -109,14 +111,13 @@ support.
not already imported, its containing package (if any) is imported, in order
to establish the package ``__path__``.
This function uses :func:`iter_importers`, and is thus subject to the same
limitations regarding platform-specific special import locations such as the
Windows registry.
.. versionchanged:: 3.3
Updated to be based directly on :mod:`importlib` rather than relying
on the package internal PEP 302 import emulation.
.. versionchanged:: 3.4
Updated to be based on :pep:`451`
.. function:: iter_importers(fullname='')

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@ -470,29 +470,22 @@ def get_loader(module_or_name):
def find_loader(fullname):
"""Find a PEP 302 "loader" object for fullname
This is s convenience wrapper around :func:`importlib.find_loader` that
sets the *path* argument correctly when searching for submodules, and
also ensures parent packages (if any) are imported before searching for
submodules.
This is a backwards compatibility wrapper around
importlib.util.find_spec that converts most failures to ImportError
and only returns the loader rather than the full spec
"""
if fullname.startswith('.'):
msg = "Relative module name {!r} not supported".format(fullname)
raise ImportError(msg)
path = None
pkg_name = fullname.rpartition(".")[0]
if pkg_name:
pkg = importlib.import_module(pkg_name)
path = getattr(pkg, "__path__", None)
if path is None:
return None
try:
return importlib.find_loader(fullname, path)
spec = importlib.util.find_spec(fullname)
except (ImportError, AttributeError, TypeError, ValueError) as ex:
# This hack fixes an impedance mismatch between pkgutil and
# importlib, where the latter raises other errors for cases where
# pkgutil previously raised ImportError
msg = "Error while finding loader for {!r} ({}: {})"
raise ImportError(msg.format(fullname, type(ex), ex)) from ex
return spec.loader
def extend_path(path, name):

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@ -334,6 +334,25 @@ class ImportlibMigrationTests(unittest.TestCase):
self.assertIsNotNone(pkgutil.get_loader("test.support"))
self.assertEqual(len(w.warnings), 0)
def test_get_loader_handles_missing_loader_attribute(self):
global __loader__
this_loader = __loader__
del __loader__
try:
with check_warnings() as w:
self.assertIsNotNone(pkgutil.get_loader(__name__))
self.assertEqual(len(w.warnings), 0)
finally:
__loader__ = this_loader
def test_find_loader_avoids_emulation(self):
with check_warnings() as w:
self.assertIsNotNone(pkgutil.find_loader("sys"))
self.assertIsNotNone(pkgutil.find_loader("os"))
self.assertIsNotNone(pkgutil.find_loader("test.support"))
self.assertEqual(len(w.warnings), 0)
def test_get_importer_avoids_emulation(self):
# We use an illegal path so *none* of the path hooks should fire
with check_warnings() as w:

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@ -20,6 +20,10 @@ Core and Builtins
Library
-------
- Issue #20839: Don't trigger a DeprecationWarning in the still supported
pkgutil.get_loader() API when __loader__ isn't set on a module (nor
when pkgutil.find_loader() is called directly).
- Issue #20778: Fix modulefinder to work with bytecode-only modules.
- Issue #20791: copy.copy() now doesn't make a copy when the input is