Sent from my iPhone > On Jan 25, 2018, at 6:51 AM, Joe <solar...@posteo.org> wrote: > > Hello, > > how I could dynamically handle the dtype of a structured array when reading > an array of C structs with np.frombuffer (regarding the member padding in the > struct). > > So far I manually adjusted the dtype of the structured array and added a > field for the padding, > this works on a small scale. > The structs are not defined within my code, but within a third party and > basically I am looking for no-worry hassle free way to handle this, because > there are a lot of structs > > Is there some smart way to do this in Numpy?
The numpy dtype constructor takes an “align” keyword that will pad it for you. However, if these strict are coming from a lib compiled by a third party, I’m not sure you can count on the alignment rules being the same. So maybe you will need to use the cffi functions :-( -CHB > > So far the best approach seems to parse the struct with the cffi functions > ffi.sizeof(), ffi.offsetof() and maybe ffi.alignof() to find out where the > padding > happens and add it dynamically to the dtype. But maybe someone has a > smarter idea how to solve this. > > You can find a more detailed description and a working example here: > > https://stackoverflow.com/questions/48423725/how-to-handle-member-padding-in-struct-when-reading-cffi-buffer-with-numpy-fromb > > Kind regards, > Joe > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@python.org > https://mail.python.org/mailman/listinfo/numpy-discussion _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@python.org https://mail.python.org/mailman/listinfo/numpy-discussion
