# Delete Row from NumPy Array that contains a specific value

In this tutorial, we will be learning how to delete a row from Numpy array that contains a specific value in Python. (Numerical Python).

You may be thinking, “This looks so easy”. Yes, You may feel that way but it is a bit tricky while programming and for that, you need to be aware of some NumPy array functions. If you are not aware, relax, because I will cover those for you. So let’s get started.

## Remove row from NumPy Array containing a specific value in Python

First of all, we need to import NumPy in order to perform the operations.

import numpy as np

You may or may not write “**as** * Your_name*“. It is done so that we do not have to write numpy again and again in our code.

*can be anything you like.*

**Your_name**Next, Using numpy, we need to create a 2D array, which is nothing but multiple lists and we need to store our array in a variable let’s say **arr.**

arr=np.array([[1,2,3],[4,5,6],[7,8,9]])

* array()* is a function used to create array which contains multiple lists separated by comma. If you do not know about creating 2D lists in python, learn here.

Now, lets declare a variable

**varĀ**that contains the

*value*whose row is to be deleted.

var=3

Now, We need to iterate the array **arr **to find our *value* inside it**. **This can be done as follows.

for i in range(0,2): for x in arr[i]: if(x==val):

After we find the value, we need to delete the containing row. For that, we use * delete()* function that takes 3 arguments.

- Array_name
- Index of containing list.
- axis (If we do not mention axis then our list gets flattened i.e, Converts into 1D array)

if axis=0, it means we are choosing row-wise deletion and if axis=1, then it means column wise deletion.

Let’s see how to do it.

if(x==val): arr=np.delete(arr,i,0)

We modified our existing array **arrĀ **with the new array which does not has the row containing the *value var=3*.

Alternatively, you can name your new array something else.

So, now we have an array which does not has the row containing the value **3**

finally, we print our array to see the required output.

print(arr)

Let’s see how our code looks like.

import numpy as np arr=np.array([[1,2,3],[4,5,6],[7,8,9]]) val=3 for i in range(0,2): for x in arr[i]: if(x==val): arr=np.delete(arr,i,0) print(arr)

**Output:**

[[4 5 6] [7 8 9]]

Also, learn

- how to find the position of an element in a list in Python
- Python | Select a random item from a list in Python

### 2 responses to “Delete Row from NumPy Array that contains a specific value”

### Leave a Reply

You must be logged in to post a comment.

Nicely explained, was looking for the same stuff

I’m glad you found it helpful.