# Python Numpy transpose() Function

Suraj Joshi Jan-25, 2021 Aug-12, 2020 NumPy

Python Numpy `numpy.transpose()` reverses the axes of the input array or simply transposes the input array.

## Syntax of `numpy.transpose()`:

``````numpy.transpose(ar,
axes=None)
``````

### Parameters

`ar` Array or Object which could be converted into an array.
`axis` Tuple or list of integers. It specifies the order of axes after permutation.

### Return

It returns transpose of the input array if it is a 2-D, however, the input array remains unchanged if it is 1-D.

## Example Codes: `numpy.transpose()` Method

``````import numpy as np

x=np.array([[2,3,3],
[3,2,1]])

print("Matrix x:")
print(x)

x_transpose=np.transpose(x)
print("\nTranspose of Matrix x:")
print(x_transpose)
``````

Output:

``````Matrix x:
[[2 3 3]
[3 2 1]]

Transpose of Matrix x:
[[2 3]
[3 2]
[3 1]]
``````

It returns the transposed version of the input array `x`. The rows of matrix `x` become columns of matrix `x_transpose` and columns of matrix `x` become rows of matrix `x_transpose`.

However, if we pass a 1-D array in the `numpy.transpose()` method, there is no change in the returned array.

``````import numpy as np

x=np.array([2,3,3])

print("Matrix x:")
print(x)

x_transpose=np.transpose(x)
print("\nTranspose of Matrix x:")
print(x_transpose)
``````

Output:

``````Matrix x:
[2 3 3]

Transpose of Matrix x:
[2 3 3]
``````

It shows 1-D array remains unchanged after passing through the `np.transpose()` method.

## Example Codes: Set `axes` Parameter in `numpy.transpose()` Method

``````import numpy as np

x = np.random.random((1, 2, 3, 5))

print("Shape of x:")
print(x.shape)

x_permuted=np.transpose(x, (3, 0, 2,1))

print("\nShape of x_permuted:")
print(x_permuted.shape)
``````

Output:

``````Shape of x:
(1, 2, 3, 5)

Shape of x_permuted:
(5, 1, 3, 2)
``````

Here, `axes` is passed as second parameter to the `numpy.transpose()` method.

The `ith` axis of the returned array will be `axes[i]-th` axis of the input array.

Hence `0th` axis in the above example of `x` becomes the first axis of `x_permuted`.