Numpy flip() Function

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The Numpy flip() function is used to reverse the order of elements in an array along a specified axis. This function is helpful when we need to rearrange array elements for data transformation or analysis. It works for both 1D and multi-dimensional arrays.

If no axis is specified, the function flips the array along all axes, effectively reversing the order of elements in all dimensions.

Syntax

Following is the syntax of the Numpy flip() function −

numpy.flip(m, axis=None)

Parameters

Following are the parameters of the Numpy flip() function −

• m: The input array to be flipped.
• axis (optional): Axis or axes along which the array is flipped. If not specified, the array is flipped along all axes.

Return Type

This function returns a view of the input array with its elements flipped along the specified axis or axes. If no axis is specified, the array is reversed completely.

Example

Following is a basic example of reversing the elements of a 1D array using the Numpy flip() function −

import numpy as np
my_array = np.array([10, 20, 30, 40, 50])
print("Original Array:", my_array)
result = np.flip(my_array)
print("Reversed Array:", result)

Output

Following is the output of the above code −

Original Array: [10 20 30 40 50]
Reversed Array: [50 40 30 20 10]

Example: Flipping Along a Specific Axis

The flip() function can flip the elements of a multi-dimensional array along a specified axis. In the following example, we have flipped the elements of a 2D array along axis 0 (rows) −

import numpy as np
my_array = np.array([[1, 2], [3, 4], [5, 6]])
print("Original Array:\n", my_array)
result = np.flip(my_array, axis=0)
print("Array flipped along rows:\n", result)

Output

Following is the output of the above code −

Original Array:
 [[1 2]
  [3 4]
  [5 6]]
Array flipped along rows:
 [[5 6]
  [3 4]
  [1 2]]

Example: Flipping Along Columns

We can also flip the elements of a 2D array along axis 1 (columns). In the following example, we flip the elements of the same array along axis 1 −

import numpy as np
my_array = np.array([[1, 2], [3, 4], [5, 6]])
print("Original Array:\n", my_array)
result = np.flip(my_array, axis=1)
print("Array flipped along columns:\n", result)

Output

Following is the output of the above code −

Original Array:
 [[1 2]
  [3 4]
  [5 6]]
Array flipped along columns:
 [[2 1]
  [4 3]
  [6 5]]

Example: Flipping Across All Axes

If no axis is specified, the flip() function reverses the array along all axes. Here, we have completely reversed the elements of the 2D array −

import numpy as np
my_array = np.array([[1, 2], [3, 4], [5, 6]])
print("Original Array:\n", my_array)
result = np.flip(my_array)
print("Array completely flipped:\n", result)

Output

Following is the output of the above code −

Original Array:
 [[1 2]
  [3 4]
  [5 6]]
Array completely flipped:
 [[6 5]
  [4 3]
  [2 1]]