Group Array by target index Python

Question

Am trying to create a groups from the array by target index

for example this my Array

Am trying to target index [1] of each child of the data array

data = [('0', 'COL1', 'date'),('1', 'COL2', 'date'), ('2', 'COL1', 'date'), ('3', 'COL3', 'date') , ('4', 'COL1', 'date'),('6', 'COL2', 'date')]

expected output is

[[('0', 'COL1', 'date'),('2', 'COL1', 'date'),('4', 'COL1', 'date')],[('1', 'COL2', 'date'),('6', 'COL2', 'date')],[('3', 'COL3', 'date')]]

Thank you any help will appreciated!

Trying to find you a duplicate that explains it but it comes up a lot of times: you basically sort it by the key and materialise the grouped items as a list, then group it by the key, eg: [list(g) for k, g in groupby(sorted(data, key=lambda L: L[1]), lambda L: L[1])] — Jon Clements
– Jon Clements, Commented Sep 21, 2019 at 13:19

wjandrea · Accepted Answer · 2019-09-21 13:41:22Z

1

import numpy as np
data = np.array(data)
data[data[:,1].argsort()]

wjandrea

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answered Sep 21, 2019 at 13:19

Ashutosh Parida

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3 Comments

am having issue printing out data[data[:,1].argsort()] but its ok, this line is enough np.array(data)

What is the issue you are facing with printing?

That will give numpy array, incase you like you can convert to list: data[data[:,1].argsort()].tolist()