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You can use the following methods to use the NumPy where() function with multiple conditions:

**Method 1: Use where() with OR**

#select values less than fiveorgreater than 20 x[np.where((x 5) | (x > 20))]

**Method 2: Use where() with AND**

#select values greater than fiveandless than 20 x[np.where((x > 5) & (x 20))]

The following example shows how to use each method in practice.

**Method 1: Use where() with OR**

The following code shows how to select every value in a NumPy array that is less than 5 **or** greater than 20:

import numpy as np #define NumPy array of values x = np.array([1, 3, 3, 6, 7, 9, 12, 13, 15, 18, 20, 22]) #select values that meet one of two conditions x[np.where((x 5) | (x > 20))] array([ 1, 3, 3, 22])

Notice that four values in the NumPy array were less than 5 **or** greater than 20.

You can also use the **size** function to simply find how many values meet one of the conditions:

#find number of values that are less than 5 or greater than 20 (x[np.where((x 5) | (x > 20))]).size 4

**Method 2: Use where() with AND**

The following code shows how to select every value in a NumPy array that is greater than 5 **and **less than 20:

import numpy as np #define NumPy array of values x = np.array([1, 3, 3, 6, 7, 9, 12, 13, 15, 18, 20, 22]) #select values that meet two conditions x[np.where((x > 5) & (x 20))] array([6, 7, 9, 12, 13, 15, 18])

The output array shows the seven values in the original NumPy array that were greater than 5 **and** less than 20.

Once again, you can use the **size** function to find how many values meet both conditions:

#find number of values that are greater than 5 and less than 20 (x[np.where((x > 5) & (x 20))]).size 7

**Additional Resources**

The following tutorials explain how to perform other common operations in NumPy:

How to Calculate the Mode of NumPy Array

How to Find Index of Value in NumPy Array

How to Map a Function Over a NumPy Array