Saving numpy array to txt file as a single column?

Question

I'm trying to write a numpy array into txt file:

a = numpy.array([1,2,3])
numpy.savetxt('a.txt',a,fmt='%.3f')

when I open the txt file it looks like:

1.0002.0003.000

but when I paste it in word it looks like:

The problem is that another program reads the txt file as input line by line:

data = fid.readlines()

As a result it doesn't work correctly.How can I fix this problem?

I'm not 100% sure on the details, but I do know that windows, mac os, and linux use different characters for their newlines. \n (carriage return) for unix/linux, \r (linefeed) for mac os, and \n\r in windows. Open up the file in python and do print(repr(fid.read())) and see if what type of newlines it contains. — Joel Cornett
– Joel Cornett, Commented Aug 1, 2012 at 8:50

bmu · Accepted Answer · 2012-11-20 18:26:07Z

1

numpy.savetxt has a keyword argument newline which defaults to \n (the unix/linux line break).

You can either set it manually or use os.linesep to choose the newline character of your current operating system. So

import os
import numpy as np

a = np.array([1,2,3])
np.savetxt('a.txt', a, fmt='%.3f', newline=os.linesep)

should be in one column with a windows editor and a program which runs under windows should be able to read it.

answered Nov 6, 2012 at 20:34

bmu

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1 Comment

Nice. Also, some better text editors (Geany, Notepad++, etc.) can handle this issue automatically in Windows.