Selecting multiple columns in Pandas - Mini Project: Build & Apply

Selecting multiple columns

📖 Scenario: You work in a small bookstore. You have a list of books with details like title, author, year, and price. You want to look at only the title and price columns to decide which books to promote.

🎯 Goal: Learn how to select multiple columns from a pandas DataFrame to focus on specific information.

📋 What You'll Learn

Create a pandas DataFrame with book data

Create a list of column names to select

Select multiple columns from the DataFrame using the list

Print the selected columns

💡 Why This Matters

🌍 Real World

Selecting specific columns helps you focus on important data, like prices and titles, when working with large datasets.

💼 Career

Data analysts and scientists often select multiple columns to prepare data for reports, visualizations, or further analysis.

1

Create the book DataFrame

Import pandas as pd and create a DataFrame called books with these exact columns and rows:
'Title': 'The Alchemist', '1984', 'Python 101'
'Author': 'Paulo Coelho', 'George Orwell', 'Michael Driscoll'
'Year': 1988, 1949, 2019
'Price': 10.99, 8.99, 29.99

Pandas

# Your code here

Need a hint?

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

2

Create a list of columns to select

Create a list called cols_to_select containing the exact strings 'Title' and 'Price'.

Pandas

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Alchemist', '1984', 'Python 101'],
    'Author': ['Paulo Coelho', 'George Orwell', 'Michael Driscoll'],
    'Year': [1988, 1949, 2019],
    'Price': [10.99, 8.99, 29.99]
})

# Create a list called cols_to_select with 'Title' and 'Price'
# Your code here

Need a hint?

Use square brackets to create a list with the two column names as strings.

3

Select the columns from the DataFrame

Create a new DataFrame called selected_books by selecting the columns in cols_to_select from the books DataFrame.

Pandas

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Alchemist', '1984', 'Python 101'],
    'Author': ['Paulo Coelho', 'George Orwell', 'Michael Driscoll'],
    'Year': [1988, 1949, 2019],
    'Price': [10.99, 8.99, 29.99]
})

cols_to_select = ['Title', 'Price']

# Select the columns in cols_to_select from books and save to selected_books
# Your code here

Need a hint?

Use books[cols_to_select] to select multiple columns by passing the list inside square brackets.

4

Print the selected columns

Print the selected_books DataFrame to see only the Title and Price columns.

Pandas

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Alchemist', '1984', 'Python 101'],
    'Author': ['Paulo Coelho', 'George Orwell', 'Michael Driscoll'],
    'Year': [1988, 1949, 2019],
    'Price': [10.99, 8.99, 29.99]
})

cols_to_select = ['Title', 'Price']

selected_books = books[cols_to_select]

# Print the selected_books DataFrame
# Your code here

Need a hint?

Use print(selected_books) to display the DataFrame with only the selected columns.