This tutorial will discuss about unique ways to remove elements from array that are not in another array – Python.

Suppose we have two NumPy Arrays,

mainArray = np.array([14, 23, 30, 41, 53]) otherArray = np.array([23, 41])

Now we want to remove only those elements from the `mainArray`

which are not present in the `otherArray`

. Basically we want to keep the common values and delete all the or different values from the `mainArray`

.

We will create a boolean mask, equal to the size of the `mainArray`

using the `numpy.isin()`

function. In which we will pass both the arrays as arguments.

# Create a boolean mask equal to the size of mainArray # Each True value in mask denotes that the corresponding # value from mainArray is present in otherArray mask = np.isin(mainArray, otherArray)

It will return a boolean array, where each True value denotes at the corresponding value in `mainArray`

is present in the `otherArray`

. Then using the mask we will select only those values from the `mainArray`

where this boolean sequence contains True value.

# Use the mask to select only those values from mainArray # where mask contains the True value at respective place mainArray = mainArray[mask]

Basically we selected only the elements from mainArray which were present in the `otherArray`

.

**Let’s see the complete example,**

### Frequently Asked:

- Remove rows with NaN values from Numpy Array – Python
- How to Remove Element from a NumPy Array?
- Remove The Middle Element from a NumPy Array
- Remove Last element from a NumPy Array in Python

import numpy as np # Create two NumPy Arrays mainArray = np.array([14, 23, 30, 41, 53]) otherArray = np.array([23, 41]) # Create a boolean mask equal to the size of mainArray # Each True value in mask denotes that the corresponding # value from mainArray is present in otherArray mask = np.isin(mainArray, otherArray) # Use the mask to select only those values from mainArray # where mask contains the True value at respective place mainArray = mainArray[mask] # Print the numpy array print(mainArray)

**Output**

[23 41]

## Summary

We learned how to Remove Elements From a NumPy Array that are not present in Another NumPy Array in Python.