Shuffle ordering of some rows in numpy array
You can use np.random.shuffle. This shuffles the rows themselves, not the elements within the rows.
From the docs:
This function only shuffles the array along the first index of a multi-dimensional array
As an example:
import numpy as npdef shuffle_rows(arr,rows): np.random.shuffle(arr[rows[0]:rows[1]+1])a = np.arange(20).reshape(4, 5)print(a)# array([[ 0, 1, 2, 3, 4],# [ 5, 6, 7, 8, 9],# [10, 11, 12, 13, 14],# [15, 16, 17, 18, 19]])shuffle_rows(a,[1,3])print(a)#array([[ 0, 1, 2, 3, 4],# [10, 11, 12, 13, 14],# [15, 16, 17, 18, 19],# [ 5, 6, 7, 8, 9]])shuffle_rows(a,[1,3])print(a)#array([[ 0, 1, 2, 3, 4],# [10, 11, 12, 13, 14],# [ 5, 6, 7, 8, 9],# [15, 16, 17, 18, 19]])