2 Array Manipulation Routines
title: "Array manipulation routines" date: 2026-05-24T13:51:27Z
Array manipulation routines
1import numpy as np
1np.__version__
'1.11.2'
Q1. Let x be a ndarray [10, 10, 3] with all elements set to one. Reshape x so that the size of the second dimension equals 150.
[[ 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1.]
[ 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1. 1. 1.]]
Q2. Let x be array [[1, 2, 3], [4, 5, 6]]. Convert it to [1 4 2 5 3 6].
[1 4 2 5 3 6]
Q3. Let x be array [[1, 2, 3], [4, 5, 6]]. Get the 5th element.
5
Q4. Let x be an arbitrary 3-D array of shape (3, 4, 5). Permute the dimensions of x such that the new shape will be (4,3,5).
(4L, 3L, 5L)
Q5. Let x be an arbitrary 2-D array of shape (3, 4). Permute the dimensions of x such that the new shape will be (4,3).
(4L, 3L)
Q5. Let x be an arbitrary 2-D array of shape (3, 4). Insert a nex axis such that the new shape will be (3, 1, 4).
(3L, 1L, 4L)
Q6. Let x be an arbitrary 3-D array of shape (3, 4, 1). Remove a single-dimensional entries such that the new shape will be (3, 4).
(3L, 4L)
Q7. Lex x be an array
[[ 1 2 3]
[ 4 5 6].
and y be an array
[[ 7 8 9]
[10 11 12]].
Concatenate x and y so that a new array looks like
[[1, 2, 3, 7, 8, 9],
[4, 5, 6, 10, 11, 12]].
[[ 1 2 3 7 8 9]
[ 4 5 6 10 11 12]]
Q8. Lex x be an array
[[ 1 2 3]
[ 4 5 6].
and y be an array
[[ 7 8 9]
[10 11 12]].
Concatenate x and y so that a new array looks like
[[ 1 2 3]
[ 4 5 6]
[ 7 8 9]
[10 11 12]]
[[ 1 2 3]
[ 4 5 6]
[ 7 8 9]
[10 11 12]]
Q8. Let x be an array [1 2 3] and y be [4 5 6]. Convert it to [[1, 4], [2, 5], [3, 6]].
[[1 4]
[2 5]
[3 6]]
Q9. Let x be an array [[1],[2],[3]] and y be [[4], [5], [6]]. Convert x to [[[1, 4]], [[2, 5]], [[3, 6]]].
[[[1 4]]
[[2 5]]
[[3 6]]]
Q10. Let x be an array [1, 2, 3, ..., 9]. Split x into 3 arrays, each of which has 4, 2, and 3 elements in the original order.
[array([1, 2, 3, 4]), array([5, 6]), array([7, 8, 9])]
Q11. Let x be an array
[[[ 0., 1., 2., 3.],
[ 4., 5., 6., 7.]],
[[ 8., 9., 10., 11.],
[ 12., 13., 14., 15.]]].
Split it into two such that the first array looks like
[[[ 0., 1., 2.],
[ 4., 5., 6.]],
[[ 8., 9., 10.],
[ 12., 13., 14.]]].
and the second one look like:
[[[ 3.],
[ 7.]],
[[ 11.],
[ 15.]]].
[array([[[ 0, 1, 2],
[ 4, 5, 6]],
[[ 8, 9, 10],
[12, 13, 14]]]), array([[[ 3],
[ 7]],
[[11],
[15]]])]
Q12. Let x be an array
[[ 0., 1., 2., 3.],
[ 4., 5., 6., 7.],
[ 8., 9., 10., 11.],
[ 12., 13., 14., 15.]].
Split it into two arrays along the second axis.
[array([[ 0, 1],
[ 4, 5],
[ 8, 9],
[12, 13]]), array([[ 2, 3],
[ 6, 7],
[10, 11],
[14, 15]])]
Q13. Let x be an array
[[ 0., 1., 2., 3.],
[ 4., 5., 6., 7.],
[ 8., 9., 10., 11.],
[ 12., 13., 14., 15.]].
Split it into two arrays along the first axis.
[array([[0, 1, 2, 3],
[4, 5, 6, 7]]), array([[ 8, 9, 10, 11],
[12, 13, 14, 15]])]
Q14. Let x be an array [0, 1, 2]. Convert it to
[[0, 1, 2, 0, 1, 2],
[0, 1, 2, 0, 1, 2]].
[[0 1 2 0 1 2]
[0 1 2 0 1 2]]
Q15. Let x be an array [0, 1, 2]. Convert it to
[0, 0, 1, 1, 2, 2].
[0 0 1 1 2 2]
Q16. Let x be an array [0, 0, 0, 1, 2, 3, 0, 2, 1, 0].
remove the leading the trailing zeros.
[1 2 3 0 2 1]
Q17. Let x be an array [2, 2, 1, 5, 4, 5, 1, 2, 3]. Get two arrays of unique elements and their counts.
[1 2 3 4 5] [2 3 1 1 2]
Q18. Lex x be an array
[[ 1 2]
[ 3 4].
Flip x along the second axis.
[[2 1]
[4 3]]
Q19. Lex x be an array
[[ 1 2]
[ 3 4].
Flip x along the first axis.
[[3 4]
[1 2]]
Q20. Lex x be an array
[[ 1 2]
[ 3 4].
Rotate x 90 degrees counter-clockwise.
[[2 4]
[1 3]]
Q21 Lex x be an array
[[ 1 2 3 4]
[ 5 6 7 8].
Shift elements one step to right along the second axis.
[[4 1 2 3]
[8 5 6 7]]