[Numpy-discussion] using numpy.savetxt to save columns of numerical values and columns of text values

Gökhan Sever gokhansever at gmail.com
Fri Nov 27 00:55:26 EST 2009

On Thu, Nov 26, 2009 at 11:30 PM, Richared Beare <
richard.beare at sci.monash.edu.au> wrote:

> I have been unable to find a way of doing a very simple thing: saving
> data that contains both arrays of numerical values and arrays of string
> values, using savetxt in numpy.
> As a very simple example, suppose a is a numpy array of integers and b
> is one containing strings, e.g.:
>    a = np.array([1,2,3])
>    b = np.array(['one', 'two', 'three'])
> The following call to savetxt:
>    savetxt('test.txt', transpose((a,b)), fmt='%i %s')
> produces the following error:
>    float argument required, not numpy.string_
> I don't have any problems if I mix integers and floats in the format
> string, or save all values as strings, but I am completely unable to
> save formatted numerical values and strings in different columns using
> savetxt.
> There must be an easy solution!

Seemingly savetxt('test.txt', transpose((a,b)), fmt='%s %s')  ; replacing
the %i with %s works. However you can't control the output precision while
saving the data into a file.

> Thank you.
> Richard Beare
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20091126/56e7c71d/attachment.html>

More information about the NumPy-Discussion mailing list