Need help with an array problem.

[Robert Kern]

SpreadTooThin wrote:
> Robert Kern wrote:
>> jakobsg at gmail.com wrote:
>>> To your question on casting long to short. This is how:
>>> a=1234L     # long
>>> b=int(a)       # int (short)
>> No, a Python int is a C long. A Python long is an arbitrary-precision number and
>> does not correspond to any C type.
> 
> So there is no short(number) casting?

Not in core Python, no, since C short ints have no Python type directly 
corresponding to them. As John Machin pointed out, if you had tried what you 
proposed, it would have worked just fine.

If you find that you keep needing to deal with the various C integer and 
floating point types (and arrays of such), you might want to consider using numpy.

   http://numpy.scipy.org


In [15]: import numpy

In [16]: a = numpy.array([65537], dtype=numpy.uint32)

In [17]: a
Out[17]: array([65537], dtype='uint32')

In [18]: b = a.astype(numpy.uint16)

In [19]: b
Out[19]: array([1], dtype='uint16')

In [20]: numpy.uint16(a[0])
Out[20]: 1


-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco