Single element access in NumPy - Mini Project: Build & Apply

Single Element Access in NumPy Arrays

📖 Scenario: You are working with temperature data collected from sensors placed in a small greenhouse. The data is stored in a 2D array where each row represents a day and each column represents a sensor reading at a specific time.

🎯 Goal: Learn how to access a single temperature reading from a NumPy 2D array using row and column indices.

📋 What You'll Learn

Create a 2D NumPy array with exact temperature values

Define variables for row and column indices

Access a single element from the array using these indices

Print the accessed temperature value

💡 Why This Matters

🌍 Real World

Accessing single data points from arrays is common in sensor data analysis, image processing, and scientific computing.

💼 Career

Data scientists and analysts often need to extract specific values from large datasets stored in arrays for detailed inspection or further processing.

1

Create the temperature data array

Import NumPy as np and create a 2D NumPy array called temperatures with these exact values: [[22, 23, 21], [20, 19, 22], [23, 24, 25]]

NumPy

# Import numpy and create the temperatures array
# Your code here

Need a hint?

Use np.array() to create the 2D array with the exact values given.

2

Set the row and column indices

Create two variables called row_index and col_index and set them to 1 and 2 respectively to select the temperature from the second day and third sensor.

NumPy

import numpy as np

temperatures = np.array([[22, 23, 21], [20, 19, 22], [23, 24, 25]])

# Set row_index and col_index to 1 and 2
# Your code here

Need a hint?

Remember that Python uses zero-based indexing, so 1 means the second row and 2 means the third column.

3

Access the single temperature element

Use the variables row_index and col_index to access the single temperature value from the temperatures array and store it in a variable called selected_temp.

NumPy

import numpy as np

temperatures = np.array([[22, 23, 21], [20, 19, 22], [23, 24, 25]])

row_index = 1
col_index = 2

# Access the element at row_index and col_index
# Your code here

Need a hint?

Use temperatures[row_index, col_index] to get the single element.

4

Print the selected temperature

Print the variable selected_temp to display the temperature value you accessed.

NumPy

import numpy as np

temperatures = np.array([[22, 23, 21], [20, 19, 22], [23, 24, 25]])

row_index = 1
col_index = 2

selected_temp = temperatures[row_index, col_index]

# Print the selected temperature
# Your code here

Need a hint?

Use print(selected_temp) to show the value.