Sample() for random rows in Data Analysis Python - Mini Project: Build & Apply

Using Sample() to Select Random Rows from Data

📖 Scenario: You work in a small bookstore. You have a list of books with their prices and want to randomly pick some books to check their condition.

🎯 Goal: Learn how to use the sample() method in pandas to select random rows from a dataset.

📋 What You'll Learn

Create a pandas DataFrame with book data

Set a variable for the number of random rows to select

Use the sample() method to pick random rows

Print the selected random rows

💡 Why This Matters

🌍 Real World

Random sampling helps quality check a few items from a large list without checking everything.

💼 Career

Data scientists often use random sampling to explore data or create training and testing sets.

1

Create the books DataFrame

Import pandas as pd and create a DataFrame called books with these exact entries: 'Title' as ['The Alchemist', '1984', 'To Kill a Mockingbird', 'The Great Gatsby', 'Moby Dick'], and 'Price' as [10.99, 8.99, 12.5, 9.75, 11.0].

Data Analysis Python

# Import pandas and create the books DataFrame with the given titles and prices
# Your code here

Need a hint?

Use pd.DataFrame() with a dictionary where keys are column names and values are lists of data.

2

Set the number of random rows to select

Create a variable called num_samples and set it to 2 to select two random rows.

Data Analysis Python

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Alchemist', '1984', 'To Kill a Mockingbird', 'The Great Gatsby', 'Moby Dick'],
    'Price': [10.99, 8.99, 12.5, 9.75, 11.0]
})

# Create num_samples variable and set it to 2
# Your code here

Need a hint?

Just assign the number 2 to the variable num_samples.

3

Select random rows using sample()

Use the sample() method on the books DataFrame with the argument n=num_samples and save the result in a variable called random_books.

Data Analysis Python

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Alchemist', '1984', 'To Kill a Mockingbird', 'The Great Gatsby', 'Moby Dick'],
    'Price': [10.99, 8.99, 12.5, 9.75, 11.0]
})

num_samples = 2

# Use sample() to select random rows and save to random_books
# Your code here

Need a hint?

Call books.sample(n=num_samples) and assign it to random_books.

4

Print the random rows

Print the variable random_books to display the randomly selected rows.

Data Analysis Python

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Alchemist', '1984', 'To Kill a Mockingbird', 'The Great Gatsby', 'Moby Dick'],
    'Price': [10.99, 8.99, 12.5, 9.75, 11.0]
})

num_samples = 2

random_books = books.sample(n=num_samples)

# Print the random_books DataFrame
# Your code here

Need a hint?

Use print(random_books) to show the selected rows. The exact rows will vary because of randomness.