how to save a boolean numpy array to textfile in python?

Question

The following saves floating values of a matrix into textfiles

numpy.savetxt('bool',mat,fmt='%f',delimiter=',')

How to save a boolean matrix ? what is the fmt for saving boolean matrix ?

If the main aim is to load the file back, why do you want to use a text file? The binary representation used by numpy.load() and numpy.save() will be much more efficient. — Sven Marnach
– Sven Marnach, Commented Jun 19, 2012 at 11:45
Do you need np.savetxt/np.loadtxt? How about np.save/np.load? — eumiro
– eumiro, Commented Jun 19, 2012 at 11:45
Why not try '%d', In python, True/False are ints, so I don't see any reason why that wouldn't work. — mgilson
– mgilson, Commented Jun 19, 2012 at 12:01

reptilicus · Accepted Answer · 2012-06-19 13:03:22Z

3

Thats correct, bools are integers, so you can always go between the two.


import numpy as np
arr = np.array([True, True, False, False])
np.savetxt("test.txt", arr, fmt="%5i")

That gives a file with 1 1 0 0

answered Jun 19, 2012 at 13:03

reptilicus

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