[Python-checkins] cpython (3.5): Issue #27487: Warn if submodule already imported before runpy execution
martin.panter
python-checkins at python.org
Sun Aug 21 01:37:04 EDT 2016
https://hg.python.org/cpython/rev/43ae044eaccc
changeset: 102818:43ae044eaccc
branch: 3.5
parent: 102816:37bc126f3473
user: Martin Panter <vadmium+py at gmail.com>
date: Sun Aug 21 04:07:58 2016 +0000
summary:
Issue #27487: Warn if submodule already imported before runpy execution
Also try to clarify the find_spec() error message.
files:
Lib/runpy.py | 11 +++++-
Lib/test/test_cmd_line_script.py | 8 ++-
Lib/test/test_runpy.py | 40 ++++++++++++++++---
Misc/NEWS | 4 ++
4 files changed, 52 insertions(+), 11 deletions(-)
diff --git a/Lib/runpy.py b/Lib/runpy.py
--- a/Lib/runpy.py
+++ b/Lib/runpy.py
@@ -114,6 +114,15 @@
if e.name is None or (e.name != pkg_name and
not pkg_name.startswith(e.name + ".")):
raise
+ # Warn if the module has already been imported under its normal name
+ existing = sys.modules.get(mod_name)
+ if existing is not None and not hasattr(existing, "__path__"):
+ from warnings import warn
+ msg = "{mod_name!r} found in sys.modules after import of " \
+ "package {pkg_name!r}, but prior to execution of " \
+ "{mod_name!r}; this may result in unpredictable " \
+ "behaviour".format(mod_name=mod_name, pkg_name=pkg_name)
+ warn(RuntimeWarning(msg))
try:
spec = importlib.util.find_spec(mod_name)
@@ -121,7 +130,7 @@
# 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 spec for {!r} ({}: {})"
+ msg = "Error while finding module specification for {!r} ({}: {})"
raise error(msg.format(mod_name, type(ex).__name__, ex)) from ex
if spec is None:
raise error("No module named %s" % mod_name)
diff --git a/Lib/test/test_cmd_line_script.py b/Lib/test/test_cmd_line_script.py
--- a/Lib/test/test_cmd_line_script.py
+++ b/Lib/test/test_cmd_line_script.py
@@ -426,8 +426,9 @@
# Exercise error reporting for various invalid package executions
tests = (
('builtins', br'No code object available'),
- ('builtins.x', br'Error while finding spec.*AttributeError'),
- ('builtins.x.y', br'Error while finding spec.*'
+ ('builtins.x', br'Error while finding module specification.*'
+ br'AttributeError'),
+ ('builtins.x.y', br'Error while finding module specification.*'
br'ImportError.*No module named.*not a package'),
('os.path', br'loader.*cannot handle'),
('importlib', br'No module named.*'
@@ -450,7 +451,8 @@
with open('test_pkg/__init__.pyc', 'wb'):
pass
err = self.check_dash_m_failure('test_pkg')
- self.assertRegex(err, br'Error while finding spec.*'
+ self.assertRegex(err,
+ br'Error while finding module specification.*'
br'ImportError.*bad magic number')
self.assertNotIn(b'is a package', err)
self.assertNotIn(b'Traceback', err)
diff --git a/Lib/test/test_runpy.py b/Lib/test/test_runpy.py
--- a/Lib/test/test_runpy.py
+++ b/Lib/test/test_runpy.py
@@ -7,6 +7,7 @@
import tempfile
import importlib, importlib.machinery, importlib.util
import py_compile
+import warnings
from test.support import (
forget, make_legacy_pyc, unload, verbose, no_tracing,
create_empty_file, temp_dir)
@@ -246,7 +247,7 @@
mod_fname)
return pkg_dir, mod_fname, mod_name, mod_spec
- def _del_pkg(self, top, depth, mod_name):
+ def _del_pkg(self, top):
for entry in list(sys.modules):
if entry.startswith("__runpy_pkg__"):
del sys.modules[entry]
@@ -320,7 +321,7 @@
self._fix_ns_for_legacy_pyc(expected_ns, alter_sys)
self.check_code_execution(create_ns, expected_ns)
finally:
- self._del_pkg(pkg_dir, depth, mod_name)
+ self._del_pkg(pkg_dir)
if verbose > 1: print("Module executed successfully")
def _check_package(self, depth, alter_sys=False,
@@ -361,7 +362,7 @@
self._fix_ns_for_legacy_pyc(expected_ns, alter_sys)
self.check_code_execution(create_ns, expected_ns)
finally:
- self._del_pkg(pkg_dir, depth, pkg_name)
+ self._del_pkg(pkg_dir)
if verbose > 1: print("Package executed successfully")
def _add_relative_modules(self, base_dir, source, depth):
@@ -424,7 +425,7 @@
self.assertIn("nephew", d2)
del d2 # Ensure __loader__ entry doesn't keep file open
finally:
- self._del_pkg(pkg_dir, depth, mod_name)
+ self._del_pkg(pkg_dir)
if verbose > 1: print("Module executed successfully")
def test_run_module(self):
@@ -447,7 +448,7 @@
result = self._make_pkg("", 1, "__main__")
pkg_dir, _, mod_name, _ = result
mod_name = mod_name.replace(".__main__", "")
- self.addCleanup(self._del_pkg, pkg_dir, 1, mod_name)
+ self.addCleanup(self._del_pkg, pkg_dir)
init = os.path.join(pkg_dir, "__runpy_pkg__", "__init__.py")
exceptions = (ImportError, AttributeError, TypeError, ValueError)
@@ -470,6 +471,31 @@
else:
self.fail("Nothing raised; expected {}".format(name))
+ def test_submodule_imported_warning(self):
+ pkg_dir, _, mod_name, _ = self._make_pkg("", 1)
+ try:
+ __import__(mod_name)
+ with self.assertWarnsRegex(RuntimeWarning,
+ r"found in sys\.modules"):
+ run_module(mod_name)
+ finally:
+ self._del_pkg(pkg_dir)
+
+ def test_package_imported_no_warning(self):
+ pkg_dir, _, mod_name, _ = self._make_pkg("", 1, "__main__")
+ self.addCleanup(self._del_pkg, pkg_dir)
+ package = mod_name.replace(".__main__", "")
+ # No warning should occur if we only imported the parent package
+ __import__(package)
+ self.assertIn(package, sys.modules)
+ with warnings.catch_warnings():
+ warnings.simplefilter("error", RuntimeWarning)
+ run_module(package)
+ # But the warning should occur if we imported the __main__ submodule
+ __import__(mod_name)
+ with self.assertWarnsRegex(RuntimeWarning, r"found in sys\.modules"):
+ run_module(package)
+
def test_run_package_in_namespace_package(self):
for depth in range(1, 4):
if verbose > 1: print("Testing package depth:", depth)
@@ -524,7 +550,7 @@
try:
self.check_code_execution(create_ns, expected_ns)
finally:
- self._del_pkg(pkg_dir, depth, mod_name)
+ self._del_pkg(pkg_dir)
def test_pkgutil_walk_packages(self):
# This is a dodgy hack to use the test_runpy infrastructure to test
@@ -548,7 +574,7 @@
expected_modules.add(pkg_name + ".runpy_test")
pkg_dir, mod_fname, mod_name, mod_spec = (
self._make_pkg("", max_depth))
- self.addCleanup(self._del_pkg, pkg_dir, max_depth, mod_name)
+ self.addCleanup(self._del_pkg, pkg_dir)
for depth in range(2, max_depth+1):
self._add_relative_modules(pkg_dir, "", depth)
for finder, mod_name, ispkg in pkgutil.walk_packages([pkg_dir]):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
Core and Builtins
-----------------
+- Issue #27487: Warn if a submodule argument to "python -m" or
+ runpy.run_module() is found in sys.modules after parent packages are
+ imported, but before the submodule is executed.
+
- Issue #27558: Fix a SystemError in the implementation of "raise" statement.
In a brand new thread, raise a RuntimeError since there is no active
exception to reraise. Patch written by Xiang Zhang.
--
Repository URL: https://hg.python.org/cpython
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