Delimiter of numpy.savetxt

Question

I am trying to write a numpy array to a .txt file using numpy.savetxt. To the best I can tell, the following code follows the documentation:

z = np.array([1,2,3])
np.savetxt('testdata.txt',z,delimiter='hi')

However, the output file, opened with Notepad, shows

1.000000000000000000e+002.000000000000000000e+003.000000000000000000e+00

without the delimiter hi between the values. Any ideas why this might be? My goal is to add new lines between each value.

Answer 1

You need 2D array, axis 0 is the row, and axis 1 is the column. So I use z[None, :] to convert it to 2D array:

from StringIO import StringIO
s = StringIO()
z = np.array([1,2,3])
np.savetxt(s,z[None, :],delimiter='hi')
s.getvalue()

output:

1.000000000000000000e+00hi2.000000000000000000e+00hi3.000000000000000000e+00\n