Python numpy How to sort a ndarray based on a row

Question

how do I sort a ndarray based on one of its rows? example:

ndarray = [['a' 'b' 'c']
           ['2' '7' '6']
           ['3' '0' '1']]

I sort based on the second row and i have:

newsortedndarray = [['a' 'c' 'b']
                    ['2' '6' '7']
                    ['3' '1' '0']]

please help

sehnsucht13 · Accepted Answer · 2019-11-24 12:11:51Z

3

Use argsort function to get an order of "columns".

ndarray[:,np.argsort(ndarray[1,:])]

sehnsucht13

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answered Nov 23, 2019 at 21:26

splash58

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Comments

code-lukas · Accepted Answer · 2019-11-24 14:05:48Z

0

Alternatively, you can np.transpose() your array to make the former columns your new rows.

answered Nov 24, 2019 at 14:05

code-lukas

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but wouldnt that just give me: python [['a' '2' '3'] ['b' '7' '0'] ['c' '6' '1']]