Numpy savetxt to a string

Question

I would like to load the result of numpy.savetxt into a string. Essentially the following code without the intermediate file:

import numpy as np

def savetxts(arr):
    np.savetxt('tmp', arr)
    with open('tmp', 'rb') as f:
        return f.read()

Answer 1

For Python 3.x you can use the io module:

>>> import io
>>> s = io.BytesIO()
>>> np.savetxt(s, (1, 2, 3), '%.4f')
>>> s.getvalue()
b'1.0000\n2.0000\n3.0000\n'

>>> s.getvalue().decode()
'1.0000\n2.0000\n3.0000\n'

Note: I couldn't get io.StringIO() to work. Any ideas?