Creating boolean arrays in NumPy - Try It Yourself

Creating boolean arrays

📖 Scenario: Imagine you have a list of temperatures recorded every day for a week. You want to find out which days were warmer than 20 degrees Celsius.

🎯 Goal: You will create a boolean array that shows True for days warmer than 20 degrees and False otherwise.

📋 What You'll Learn

Use numpy to create arrays

Create a numpy array with exact temperature values

Create a boolean array using a condition

Print the boolean array as output

💡 Why This Matters

🌍 Real World

This technique helps in filtering data based on conditions, like finding days warmer than a certain temperature.

💼 Career

Data scientists often create boolean arrays to filter and analyze data quickly and efficiently.

1

Create the temperature array

Create a numpy array called temperatures with these exact values: [18, 22, 19, 24, 20, 21, 17].

NumPy

import numpy as np
# Create the numpy array called temperatures with the given values
# Your code here

Need a hint?

Use np.array([...]) to create the array with the exact numbers.

2

Set the temperature threshold

Create a variable called threshold and set it to 20.

NumPy

import numpy as np

temperatures = np.array([18, 22, 19, 24, 20, 21, 17])
# Create the threshold variable and set it to 20
# Your code here

Need a hint?

Just assign the number 20 to a variable named threshold.

3

Create the boolean array

Create a boolean numpy array called warm_days that is True where temperatures are greater than threshold, and False otherwise.

NumPy

import numpy as np

temperatures = np.array([18, 22, 19, 24, 20, 21, 17])

threshold = 20
# Create warm_days as a boolean array where temperatures are greater than threshold
# Your code here

Need a hint?

Use the comparison operator > between the array and the threshold variable.

4

Print the boolean array

Print the warm_days array to see which days were warmer than 20 degrees.

NumPy

import numpy as np

temperatures = np.array([18, 22, 19, 24, 20, 21, 17])

threshold = 20

warm_days = temperatures > threshold
# Print the warm_days array
# Your code here

Need a hint?

Use print(warm_days) to display the boolean array.