[Numpy-discussion] array of tuples (original) (raw)

David M. Cooke cookedm at physics.mcmaster.ca
Tue Jun 6 17:07:05 EDT 2006

On Tue, 06 Jun 2006 13:21:56 -0700 Christopher Barker <Chris.Barker at noaa.gov> wrote:

Travis N. Vaught wrote: > I'd like to construct an array of tuples and I'm not sure how (without > looping). Is this what you want? >>> import numpy as N >>> a = N.empty((2,),dtype=object) >>> a[:] = [(1,2,3),(4,5,6)] >>> a array([(1, 2, 3), (4, 5, 6)], dtype=object) >>> a.shape (2,) By the way, I notice that the object dtype is not in the numpy namespace. While this mikes sense, as it's part of python, I keep getting confused because I do need to use numpy-specific dtypes for other things. I never use import *, so it might be a good idea to put the standard objects dtypes in the numpy namespace too. Or maybe not, just thinking out loud.

None of the Python types are (int, float, etc.). For one reason, various Python checkers complain about overwriting a builtin type, and plus, I think it's messy and a potential for bugs. numpy takes those as convenience types, and converts them to the appropriate dtype. If you want the dtype used, it's spelled with an appended _.

So in this case you'd want dtype=N.object_. N.object0 works too.

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