Sorry I wasn't at the last Sage days, but the way I see things Numpy should be using a .pxd file.
There seems to be a lot of misunderstanding over what a pxd vs. pxi file is. A pxd file is a declaration file, it just says "these things will be available." A .pxi file is an include file, it is simply textually included at that point in the program. The confusion comes because cdef extern from blocks work the same for both. Perhaps we should get rid of .pxi files altogether and just call them .pyx files, because that's really what they are. - Robert On Apr 24, 2008, at 1:16 PM, Brian Granger wrote: > Hi, > > Previously, in numpy shipped with a numpy.pxd. But, at the last Sage > days, all the Sage folks said "no, no, you should use a .pxi file for > numpy, not a pxd file." Recently, Fernando updated the numpy example > to work with cython and renamed the file to numpy.pxi. For simple > things this works fine, but I am running into huge problems using the > renamed numpy.pxi: > > 1) In numpy,pxi, there are extension types defined: > > ctypedef extern class numpy.dtype [object PyArray_Descr]: > cdef int type_num, elsize, alignment > cdef char type, kind, byteorder, hasobject > cdef object fields, typeobj > > The problem is that when I include this .pxi file, I get the symbol > dtype dumped into my global namespace. This makes it impossible to > write functions like: > > def foo(a, dtype=float): > ^^^^^ Cython complains that this is a not a valid C > variable declaration > > So, then I thought I would get smart and do: > > ctypedef extern class numpy.dtype as DType [object PyArray_Descr]: > cdef int type_num, elsize, alignment > cdef char type, kind, byteorder, hasobject > cdef object fields, typeobj > > But, this doesn't work because in numpy.pxi there are other extern > classes defined that use dtype. Even when I change those references > to DType, Cython complains that it doesn't know what DType is. > > 2) I have various files that are independent that need to include > numpy.pxi. This works fine. But, when I use a file that includes > numpy.pxi (through an include or cimport) in another file that > includes numpy.pxi, I get lots of problems. It looks like Cython > tries to include numpy.pxi twice. The second time it sees it, it > thinks it is finding the actual implementation of the classes and > complains that I can't add new C attributes in the implmentation. >> From this, it looks like Cython has problems with double includes of > pxi files that define extern classes. > > So.... > > The only way I can get all this to work is the rename numpy.pxi -> > c_numpy.pxd and use cimport. Then all works well. But, this seems to > go against the recommendation that pxd files should not be used for > this purpose. Also, it seems like there are bugs or misfeatures in > Cython's handling of pxi files. > > Thoughts? Thanks > > Brian > _______________________________________________ > Cython-dev mailing list > [email protected] > http://codespeak.net/mailman/listinfo/cython-dev _______________________________________________ Cython-dev mailing list [email protected] http://codespeak.net/mailman/listinfo/cython-dev
