Remove First N Elements from a NumPy Array

This tutorial will discuss about unique ways to remove first n elements from a numpy array.

Suppose we have an NumPy array of numbers. Like this,

numbers = np.array([34, 35, 78, 61, 56, 35, 90, 35])

Now we want to remove first N elements from this array. For this we are going to use the slicing feature of Python, in which we can select a portion of elements from the numpy array using the subscript operator. Like this,

arr[start : end]

It will select the elements from the array, from index position start till index position end. If we don’t provide the end index position, then it will keep picking the elements till the end of the array.

To remove first N elements of array. We can use the index N as starting point, which denotes the index position of Nth element of array. We can use the default value for end index in slicing, so that it can pick elements till the end of array.

For example, to remove first 3 elements from array, we can select elements from index 3 till the end of array. like this,

# specify number of elements to remove
n = 3

# Remove the first N elements from the array
numbers = numbers[n :]

It will remove first 3 elements from NumPy Array.

Let’s see the complete example,

import numpy as np

# create sample numpy array
numbers = np.array([34, 35, 78, 61, 56, 35, 90, 35])

print('Before removing elements:')
print(numbers)

# specify number of elements to remove
n = 3

# Remove the first N elements from the array
numbers = numbers[n :]

print('After removing elements:')
print(numbers)

Output

Before removing elements:
[34 35 78 61 56 35 90 35]
After removing elements:
[61 56 35 90 35]

Summary

We learned how to remove first N elements from a NumPy Array in Python.