More about Comparisons

Most conditions you will use are comparisons, so it's important to discuss them in more detail. Comparisons are based on the following comparison operators:

> (greater than);
< (less than);
>= (greater than or equal to);
<= (less than or equal to);
== (equal to);
!= (not equal to).

Moreover, you can combine multiple conditions and comparisons using the following logical operators:

& (logical and);
| (logical or).

If at least one of the conditions is True, then | returns True; otherwise, it returns False. If at least one of the conditions is False, then & returns False; otherwise, it returns True.

Note

Each condition should be put in parentheses () when combining them.


              1234567891011
            
import numpy as np
# Creating an array of integers from 1 to 10 inclusive
array = np.arange(1, 11)
# Retrieving elements greater than or equal to 5 AND less than 9
print(array[(array >= 5) & (array < 9)])
# Retrieving elements less than or equal to 4 AND not equal to 2
print(array[(array != 2) & (array <= 4)])
# Retrieving elements less than 3 OR equal to 8
print(array[(array < 3) | (array == 8)])
# Retrieving elements between 2 inclusive AND 5 inclusive OR equal to 9
print(array[(array >= 2) & (array <= 5) | (array == 9)])

Let's now take a look at the following visualization to understand the code better (purple squares represent the actual retrieved elements):

Task

Swipe to show code editor

You are analyzing the ratings of various products collected from customer feedback. The ratings are stored in the product_ratings array, where each element represents the rating of a product.

Use boolean indexing to filter out the ratings that are greater than or equal to 3 and not equal to 5.
Print the resulting array.

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Everything was clear?

Thanks for your feedback!

Section 2. Chapter 7

More about Comparisons

Most conditions you will use are comparisons, so it's important to discuss them in more detail. Comparisons are based on the following comparison operators:

> (greater than);
< (less than);
>= (greater than or equal to);
<= (less than or equal to);
== (equal to);
!= (not equal to).

Moreover, you can combine multiple conditions and comparisons using the following logical operators:

& (logical and);
| (logical or).

Note

Each condition should be put in parentheses () when combining them.


              1234567891011
            
import numpy as np
# Creating an array of integers from 1 to 10 inclusive
array = np.arange(1, 11)
# Retrieving elements greater than or equal to 5 AND less than 9
print(array[(array >= 5) & (array < 9)])
# Retrieving elements less than or equal to 4 AND not equal to 2
print(array[(array != 2) & (array <= 4)])
# Retrieving elements less than 3 OR equal to 8
print(array[(array < 3) | (array == 8)])
# Retrieving elements between 2 inclusive AND 5 inclusive OR equal to 9
print(array[(array >= 2) & (array <= 5) | (array == 9)])

Let's now take a look at the following visualization to understand the code better (purple squares represent the actual retrieved elements):

Task

Swipe to show code editor

You are analyzing the ratings of various products collected from customer feedback. The ratings are stored in the product_ratings array, where each element represents the rating of a product.

Use boolean indexing to filter out the ratings that are greater than or equal to 3 and not equal to 5.
Print the resulting array.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 2. Chapter 7

Switch to desktop for real-world practiceContinue from where you are using one of the options below