[Cython] Automatic buffer dtype conversion?

[Dag Sverre Seljebotn]

Magnus Lie Hetland wrote:
> Hi!
> 
> I've been trying to get the simple Cython+NumPy example from Robert  
> Bradshaw's slides to work:
> 
>> # footest.pyx
> 
>> cimport numpy
>>
>> def sum(x):
>>     cdef numpy.ndarray[int, ndim=1] arr = x
>>     cdef int i, s = 0
>>     for i in range(arr.shape[0]):
>>         s += arr[i]
>>     return s
> 
> I get it to compile/link, but then I try to actually use it, with the  
> following code:
> 
>> import footest
>> import numpy as np
>>
>> a = np.arange(1000, dtype=np.int)
>> print footest.sum(a)
> 
> The np.int shouldn't be necessary -- and I started without it -- but  
> even *with* it, I get the following error:

BTW I believe NumPy has switched the default dtype to float in recent 
versions, so better leave it in. (But I'm not 100% sure about this)
-- 
Dag Sverre