CODEWITHSUNDEEP
pythonarraysfilenumpy
D3mark0
D3mark0

Reputation: 45

Numpy savetxt saves 1D array as column

I use loadtxt to initialize array.

source = np.loadtxt('source.txt').astype(int)

After that I use this array in function, which body is:

file = open('johnson.txt', 'ab')
first = increase(np.argsort(source[0]))
np.savetxt(file, first, delimiter='-', fmt='%i')
file.close()

As a result, in txt file I should have this:

7-1-3-6-2-4-8-5

But I have this:

7
1
3
6
2
4
8
5

I have to open file in binary mode, because I need to append another rows to file. So, how can I fix that? Thank you!

Upvotes: 3

Views: 1734

Answers (1)

hpaulj
hpaulj

Reputation: 231335

savetxt iterates on the input array, and writes each 'row' to a new line. For the typical 2d array that would be a row. But for a 1d array that would be an element.

So change your write to saving a 2d array:

np.savetxt('test.txt', [first], delimiter=..., fmt=...)

Assuming first is a 1d array, then np.array([first]) is 1 row 2d, first[None,:] would also work (or a reshape).

To append lines, open the file in 'a' append mode. 'wb'` binary doesn't help.

Upvotes: 4

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