Charles R Harris wrote: > On 9/3/06, *Fernando Perez* <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> wrote: > > Hi all, > > I'm wondering if the following difference in behavior of object > arrays should > be considered a bug. Let a and b be: > > In [21]: a = [0,1] > > In [22]: b = [ None, None] > > If we concatenate a with an empty list, it works: > > In [23]: numpy.concatenate(([],a)) > Out[23]: array([0, 1]) > > But not so for b: > > In [24]: numpy.concatenate(([],b)) > > --------------------------------------------------------------------------- > exceptions.ValueError Traceback > (most recent > call last) > > /home/fperez/<ipython console> > > ValueError: 0-d arrays can't be concatenated > > > I think it's propably a bug: > > >>> concatenate((array([]),b)) > array([None, None], dtype=object)
Well, if you can fix it without breaking anything else, then it's a bug. However, I would suggest that a rule of thumb for using object arrays is to always be explicit. Never rely on automatic conversion from Python containers to object arrays. Since Python containers are also objects, it is usually ambiguous what the user meant. I kind of liked numarray's choice to move the object array into a separate constructor. I think that gave them some flexibility to choose different syntax and semantics from the generic array() constructor. Since constructing object arrays is so different from constructing numeric arrays, I think that difference is warranted. -- 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 ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Numpy-discussion mailing list Numpy-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/numpy-discussion
