Closed mvadai closed 3 years ago
kiliakis
commented
3 years ago Just to complicate things a bit more, we can add another option on the table: with platform.python_version() we can get the python version and compare it with 3.8 instead of looking for the existence of the add_dll_directory() method.
scpalbright
commented
3 years ago Just to complicate things a bit more, we can add another option on the table: with
platform.python_version()we can get the python version and compare it with 3.8 instead of looking for the existence of theadd_dll_directory()method.
Only down side of that is keep track of version numbers, which would probably be fine, but I think is potentially a little more fragile.
kiliakis
commented
3 years ago Just to complicate things a bit more, we can add another option on the table: with
platform.python_version()we can get the python version and compare it with 3.8 instead of looking for the existence of theadd_dll_directory()method.Only down side of that is keep track of version numbers, which would probably be fine, but I think is potentially a little more fragile.
Keep track of what exactly? The check will be something like if platform.python_version() >= 3.8 (adjusted for version comparison) . To me this shows more clearly that this check was put there to support something modified in python-3.8, than checking for the existence of a method which was added in python-3.8.
scpalbright
commented
3 years ago Keep track of what exactly? The check will be something like if
platform.python_version() >= 3.8(adjusted for version comparison) . To me this shows more clearly that this check was put there to support something modified in python-3.8, than checking for the existence of a method which was added in python-3.8.
I'm thinking of the, albeit unlikely, possibility that it gets changed again in a later version.
mvadai
commented
3 years ago I went for checking for the add_dll_directory method, because I wanted to check for the behaviour and not the version that does the behaviour. Furthermore this is the explicitly advised method: https://docs.python.org/3/whatsnew/3.8.html#bpo-36085-whatsnew
The dll import mechanism has changed in Windows from Python 3.8.
Instead of an external path, the dll-s are imported from the application via a new function in 3.8: https://docs.python.org/3/library/os.html#os.add_dll_directory Explanation: https://docs.python.org/3/whatsnew/3.8.html#bpo-36085-whatsnew
Furthermore, ctypes.CDLL has to specify a winmode flag how this dll should be imported, also new in 3.8. https://docs.python.org/3/library/ctypes.html#ctypes.CDLL However the default value of winmode is None and not 0 as documented. 0 has to be explicitly specified.