[Numpy-discussion] Re: array of arbitrary objects

[Albert Strasheim]

Hello all

> -----Original Message-----
> From: numpy-discussion-admin at lists.sourceforge.net [mailto:numpy-
> discussion-admin at lists.sourceforge.net] On Behalf Of Robert Kern
> Sent: 11 May 2006 05:28
> To: numpy-discussion at lists.sourceforge.net
> Subject: [Numpy-discussion] Re: array of arbitrary objects
> 
> Ryan Krauss wrote:
> > Is it possible with numpy to create arrays of arbitrary objects?
> > Specifically, I have defined a symbolic string class with operator
> > overloading for most simple math operations: 'a'*'b' ==> 'a*b'
> >
> > Can I create two matrices of these symbolic string objects and
> > multiply those matrices together?
> >
> > (simply doing array([[a,b],[c,d]]) did not work.  the symbolic strings
> > got cast to regular strings)
> 
> Use dtype=object .

How does one go about putting tuples into an object array?

Consider the following example, courtesy of Louis Cordier:

In [1]: import numpy as N
In [2]: a = [(1,2), (2,3), (3,4)]
In [3]: len(a)
Out[3]: 3
In [5]: N.array(a, 'O')
Out[5]:
array([[1, 2],
       [2, 3],
       [3, 4]], dtype=object)

instead of something like this:

array([[(1, 2), (2, 3), (3, 4)]], dtype=object)

Cheers,

Albert