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-rw-r--r--Doc/library/importlib.rst14
-rw-r--r--Lib/importlib/__init__.py24
-rw-r--r--Lib/importlib/test/test_api.py50
-rw-r--r--Lib/pyclbr.py25
-rw-r--r--Misc/NEWS2
5 files changed, 105 insertions, 10 deletions
diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
index cac5251..0bc1b65 100644
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -86,6 +86,20 @@ Functions
that was imported (e.g. ``pkg.mod``), while :func:`__import__` returns the
top-level package or module (e.g. ``pkg``).
+.. function:: find_loader(name, path=None)
+
+ Find the loader for a module, optionally within the specified *path*. If the
+ module is in :attr:`sys.modules`, then ``sys.modules[name].__loader__`` is
+ returned (unless the loader would be ``None``, in which case
+ :exc:`ValueError` is raised). Otherwise a search using :attr:`sys.meta_path`
+ is done. ``None`` is returned if no loader is found.
+
+ A dotted name does not have its parent's implicitly imported. If that is
+ desired (although not nessarily required to find the loader, it will most
+ likely be needed if the loader actually is used to load the module), then
+ you will have to import the packages containing the module prior to calling
+ this function.
+
.. function:: invalidate_caches()
Invalidate the internal caches of the finders stored at
diff --git a/Lib/importlib/__init__.py b/Lib/importlib/__init__.py
index 57fb284..90e163c 100644
--- a/Lib/importlib/__init__.py
+++ b/Lib/importlib/__init__.py
@@ -29,6 +29,30 @@ def invalidate_caches():
finder.invalidate_caches()
+def find_loader(name, path=None):
+ """Find the loader for the specified module.
+
+ First, sys.modules is checked to see if the module was already imported. If
+ so, then sys.modules[name].__loader__ is returned. If that happens to be
+ set to None, then ValueError is raised. If the module is not in
+ sys.modules, then sys.meta_path is searched for a suitable loader with the
+ value of 'path' given to the finders. None is returned if no loader could
+ be found.
+
+ Dotted names do not have their parent packages implicitly imported.
+
+ """
+ try:
+ loader = sys.modules[name].__loader__
+ if loader is None:
+ raise ValueError('{}.__loader__ is None'.format(name))
+ else:
+ return loader
+ except KeyError:
+ pass
+ return _bootstrap._find_module(name, path)
+
+
def import_module(name, package=None):
"""Import a module.
diff --git a/Lib/importlib/test/test_api.py b/Lib/importlib/test/test_api.py
index cc147c2..b7d6cb4 100644
--- a/Lib/importlib/test/test_api.py
+++ b/Lib/importlib/test/test_api.py
@@ -85,6 +85,54 @@ class ImportModuleTests(unittest.TestCase):
self.assertEqual(b_load_count, 1)
+class FindLoaderTests(unittest.TestCase):
+
+ class FakeMetaFinder:
+ @staticmethod
+ def find_module(name, path=None): return name, path
+
+ def test_sys_modules(self):
+ # If a module with __loader__ is in sys.modules, then return it.
+ name = 'some_mod'
+ with util.uncache(name):
+ module = imp.new_module(name)
+ loader = 'a loader!'
+ module.__loader__ = loader
+ sys.modules[name] = module
+ found = importlib.find_loader(name)
+ self.assertEqual(loader, found)
+
+ def test_sys_modules_loader_is_None(self):
+ # If sys.modules[name].__loader__ is None, raise ValueError.
+ name = 'some_mod'
+ with util.uncache(name):
+ module = imp.new_module(name)
+ module.__loader__ = None
+ sys.modules[name] = module
+ with self.assertRaises(ValueError):
+ importlib.find_loader(name)
+
+ def test_success(self):
+ # Return the loader found on sys.meta_path.
+ name = 'some_mod'
+ with util.uncache(name):
+ with util.import_state(meta_path=[self.FakeMetaFinder]):
+ self.assertEqual((name, None), importlib.find_loader(name))
+
+ def test_success_path(self):
+ # Searching on a path should work.
+ name = 'some_mod'
+ path = 'path to some place'
+ with util.uncache(name):
+ with util.import_state(meta_path=[self.FakeMetaFinder]):
+ self.assertEqual((name, path),
+ importlib.find_loader(name, path))
+
+ def test_nothing(self):
+ # None is returned upon failure to find a loader.
+ self.assertIsNone(importlib.find_loader('nevergoingtofindthismodule'))
+
+
class InvalidateCacheTests(unittest.TestCase):
def test_method_called(self):
@@ -114,7 +162,7 @@ class InvalidateCacheTests(unittest.TestCase):
def test_main():
from test.support import run_unittest
- run_unittest(ImportModuleTests)
+ run_unittest(ImportModuleTests, FindLoaderTests, InvalidateCacheTests)
if __name__ == '__main__':
diff --git a/Lib/pyclbr.py b/Lib/pyclbr.py
index 52cbdd5..4cd85b9 100644
--- a/Lib/pyclbr.py
+++ b/Lib/pyclbr.py
@@ -39,8 +39,10 @@ Instances of this class have the following instance variables:
lineno -- the line in the file on which the class statement occurred
"""
+import io
+import os
import sys
-import imp
+import importlib
import tokenize
from token import NAME, DEDENT, OP
from operator import itemgetter
@@ -133,19 +135,24 @@ def _readmodule(module, path, inpackage=None):
# Search the path for the module
f = None
if inpackage is not None:
- f, fname, (_s, _m, ty) = imp.find_module(module, path)
+ search_path = path
else:
- f, fname, (_s, _m, ty) = imp.find_module(module, path + sys.path)
- if ty == imp.PKG_DIRECTORY:
- dict['__path__'] = [fname]
- path = [fname] + path
- f, fname, (_s, _m, ty) = imp.find_module('__init__', [fname])
+ search_path = path + sys.path
+ loader = importlib.find_loader(fullmodule, search_path)
+ fname = loader.get_filename(fullmodule)
_modules[fullmodule] = dict
- if ty != imp.PY_SOURCE:
+ if loader.is_package(fullmodule):
+ dict['__path__'] = [os.path.dirname(fname)]
+ try:
+ source = loader.get_source(fullmodule)
+ if source is None:
+ return dict
+ except (AttributeError, ImportError):
# not Python source, can't do anything with this module
- f.close()
return dict
+ f = io.StringIO(source)
+
stack = [] # stack of (class, indent) pairs
g = tokenize.generate_tokens(f.readline)
diff --git a/Misc/NEWS b/Misc/NEWS
index 78a5ef9..a7d1b44 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -23,6 +23,8 @@ Core and Builtins
Library
-------
+- Issue #13959: Introduce importlib.find_loader().
+
- Issue #14082: shutil.copy2() now copies extended attributes, if possible.
Patch by Hynek Schlawack.