How to Use the Numpy transpose() Method in Python

Numpy.transpose() method is “used to get the permute or reserve the dimension of the input array, meaning it converts the row elements into column elements and the column elements into row elements.”

Syntax

numpy.transpose(a, axes=None)

Parameters

  1. a: array_like: It is the Input array.
  2. axes: tuple or list of ints, optional: If specified, it must be the tuple or list, which contains the permutation of [0,1,.., N-1] where N is the number of axes of a. The i’th axis of the returned array will correspond to an axis numbered axes[i] of the input.  If not specified, defaults to the range(a.ndim)[::-1], which reverses the order of the axes.

Return value

The np.transpose() method returns an array with its axes permuted. A view is returned whenever possible.

Example 1: How to Use np.transpose() Method

import numpy as np

data = np.arange(6).reshape((2, 3))
print("Original Array")
print(data)

tMat = np.transpose(data)
print("Transposed Array")
print(tMat)

Output

Original Array
[[0 1 2]
 [3 4 5]]
Transposed Array
[[0 3]
 [1 4]
 [2 5]]

Example 2: Using the T attribute

In Python, you can get a transposed matrix of the original two-dimensional array (matrix) with the T attribute.

import numpy as np

arr2d = np.arange(6).reshape(2, 3)
print(arr2d)
print('\n')
print('After using T attribute: ')
arr2d_T = arr2d.T
print(arr2d_T)

Output

[[0 1 2]
 [3 4 5]]


After using T attribute:
[[0 3]
 [1 4]
 [2 5]]

Example 3: Provide an ndarray

The transpose() is provided as a method of ndarray. Like T, the view is returned.

import numpy as np

arr2d = np.arange(6).reshape(2, 3)
print(arr2d)
print('\n')
print('After using transpose() function: ')
arr2d_T = arr2d.transpose()
print(arr2d_T)

Output

[[0 1 2]
 [3 4 5]]


After using transpose() function:
[[0 3]
 [1 4]
 [2 5]]

You can see that we got the same output as above. 

That’s it.

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