[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
New submission from Etienne Fortin: The pywin32 package use imp.load_dynamic() to load a DLL with Windows specific type. On Python 3.4+ imp.load_dynamic() point to the following code which use the newer importlib module: import importlib.machinery loader = importlib.machinery.ExtensionFileLoader(name, path) return loader.load_module() In pywin32 a mechanism is used to be able to have part of a module globals defined in python (pywintypes.py), and the reminder in a DLL (pywintypesXX.dll). The code in pywin32 between 3.4 and 3.5 is the same. In Python 3.4, calling imp.load_dynamic(), which point to the code above, inside the python part of the module definition loads the types defined in the DLL. In Python 3.5, calling imp.load_dynamic(), which also points to the code above, inside the python part of the module definition reloads the same python module, not the DLL. Even though a path to a DLL is given AND when doing introspection of the module it clearly points to the specified DLL. This is a change of behavior that breaks pywin32, but possibly other modules that rely on this behavior. -- components: Extension Modules, Windows files: pywintypes.py messages: 247573 nosy: ebfortin, paul.moore, steve.dower, tim.golden, zach.ware priority: normal severity: normal status: open title: Change of behavior for importlib between 3.4 and 3.5 with DLL loading type: behavior versions: Python 3.5 Added file: http://bugs.python.org/file40055/pywintypes.py ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
Etienne Fortin added the comment: It is also possible that the root cause is related to Microsoft Windows Update 2999226 and/or 3065987. The behavior was the same between 3.4 and 3.5 on a machine without these updates and is believed to have changed after the install of these updates. -- ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
Etienne Fortin added the comment: No the behavior only changed for 3.5. 3.4 works just fine. -- ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
Etienne Fortin added the comment: I suggest the test should use pywin32. The test script could be only: import pywintypes dir(pywintypes) Testing for an attribute that is defined in the DLL would make it pass or fail. -- ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
Etienne Fortin added the comment: At this point I can't say if it's Windows only or if it affect all platform. I can't even guarantee that it will appear on all Windows platform. On my platform (see following), it doesn't work: Windows 7 64 bits with updates 2999226 and 3065987 installed. I can't confirm the update are related either. I just did a quick analysis and between the time 3.5 was working and wasn't anymore these updates were installed. I will create a quick script to reproduce the behavior. -- ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
Etienne Fortin added the comment: The only dll / pyd files I have are all in pywin32. I don't have a build environment for extensions. Can anyone provide me with a very simple extension DLL with at least one exported attribute? -- ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
Etienne Fortin added the comment: Is it possible that the C runtime introduced with 2999226, which I believe is the "universal runtime" Microsoft is trying to introduce, modified something that makes importlib break on 3.5??? -- ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24748] Change of behavior for importlib between 3.4 and 3.5 with DLL loading
Etienne Fortin added the comment: I replaced: import importlib.machinery loader = importlib.machinery.ExtensionFileLoader(name, path) return loader.load_module() With: import importlib.machinery loader = importlib.machinery.ExtensionFileLoader(modname, filename) spec = importlib.machinery.ModuleSpec( name = modname, loader = loader, origin = filename, loader_state = 1234, is_package = False, ) mod = loader.create_module(spec) loader.exec_module(mod) And it now works as advertised. Since load_module() is flagged as Deprecated, I believe no correction is necessary as the preffered way to load a module, with exec_module(), is working. I will do some more tests to be sure it's the case. -- ___ Python tracker <http://bugs.python.org/issue24748> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
