On 3/26/07, Alan G Isaac <aisaac@american.edu> wrote:
finds itself in basic conflict with the idea that I ought to be able to iterate over the objects in an iterable container. I mean really, does this not "feel" wrong? :: >>> for item in x: print item.__repr__() >>> ... >>> matrix([[1, 2]]) >>> matrix([[3, 4]])
On Mon, 26 Mar 2007, Bill Baxter apparently wrote:
So you're saying this is what you'd find more pythonic?
X[1] matrix([2,3]) X[:,1] matrix([[3, 4]]) Just trying to make it clear what you're proposing.
No; that is not possible, since a matrix is inherently 2d. I just want to get the constituent arrays when I iterate over the matrix object or use regular Python indexing, but a matrix when I use matrix/array indexing. That is :: >>> X[1] array([2,3]) >>> X[1,:] matrix([[3, 4]]) That behavior seems completely natural and unsurprising.
Probably about half the bugs I get from mixing and matching matrix and array are things like row = A[i] ... z = row[2] Which works for an array but not for a matrix.
Exactly! That is the evidence of a "bad surprise" in the current behavior. Iterating over a Python iterable should provide access to the contained objects. Cheers, Alan Isaac