Python | Reverse a numpy array (original) (raw)

Last Updated : 16 Sep, 2022

As we know Numpy is a general-purpose array-processing package that provides a high-performance multidimensional array object, and tools for working with these arrays. Let’s discuss how can we reverse a Numpy array.

Using flip() function to Reverse a Numpy array

The numpy.flip() function reverses the order of array elements along the specified axis, preserving the shape of the array.

Python3

import numpy as np

ini_array = np.array([ 1 , 2 , 3 , 6 , 4 , 5 ])

res = np.flip(ini_array)

print ( "final array" , str (res))

Output:

final array [5 4 6 3 2 1]

Using the list slicing method to reverse a Numpy array

This method makes a copy of the list instead of sorting it in order. To accommodate all of the current components, making a clone requires additional room. More RAM is used up in this way. Here, we’re utilizing Python’s slicing method to invert our list.

Python3

import numpy as np

ini_array = np.array([ 1 , 2 , 3 , 6 , 4 , 5 ])

print ( "initial array" , str (ini_array))

print ( "type of ini_array" , type (ini_array))

res = ini_array[:: - 1 ]

print ( "final array" , str (res))

Output:

initial array [1 2 3 6 4 5] type of ini_array <class 'numpy.ndarray'> final array [5 4 6 3 2 1]

Using flipud function to Reverse a Numpy array

The numpy.flipud() function flips the array(entries in each column) in up-down direction, shape preserved.

Python3

import numpy as np

ini_array = np.array([ 1 , 2 , 3 , 6 , 4 , 5 ])

print ( "initial array" , str (ini_array))

print ( "type of ini_array" , type (ini_array))

res = np.flipud(ini_array)

print ( "final array" , str (res))

Output:

initial array [1 2 3 6 4 5] type of ini_array <class 'numpy.ndarray'> final array [5 4 6 3 2 1]