# NumPy - transpose() function

The NumPy transpose() function is used to reverse or permute the axes of an array and returns the modified array. For a 2-D array, the function returns matrix transpose.

### Syntax

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

### Parameters

 `a` `Required. `Specify the input array. `axes` `Optional. `Specify a tuple or list which contains a permutation of [0,1,..,N-1] where N is the number of axes of a. The ith axis of the returned array will correspond to the axis numbered axes[i] of the input. If not specified, defaults to range(a.ndim)[::-1], which reverses the order of the axes.

### Return Value

Returns a with its axes permuted.

### Example: matrix transpose

In the example below, the function returns matrix transpose.

```import numpy as np
Arr = np.array([[10,20,30],[100, 200,300]])

print("Array is:")
print(Arr)

#creating matrix transpose
print("\nMatrix transpose is:")
print(np.transpose(Arr))
```

The output of the above code will be:

```Array is:
[[ 10  20  30]
[100 200 300]]

Matrix transpose is:
[[ 10 100]
[ 20 200]
[ 30 300]]
```

### Example: transpose() with axes parameter

The axes parameter can be used to permute the axes of the array. Consider the following example.

```import numpy as np
#creating a 3-D array of ones
Arr1 = np.ones((10,5,2))

#permute axes
Arr2 = np.transpose(Arr1, (2,0,1))

#checking the shape of permuted array
print(Arr2.shape)
```

The output of the above code will be:

```(2, 10, 5)
```

❮ NumPy - Functions

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