Python 2.7.3 (default, Apr 20 2012, 22:39:59)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import spam, numpy
>>> a = spam.vector3d()
>>> a[0]=1
>>> b = numpy.array(a, copy=False)
>>> b
array([ 1.,  0.,  0.])
>>> a[1]=1
>>> b
array([ 1.,  1.,  0.])
>>> a = 0
>>> b
array([ 1.,  1.,  0.])
>>> a
0
>>>