str.len() for string length in Pandas - Mini Project: Build & Apply

Using str.len() to Find String Lengths in a DataFrame

📖 Scenario: You work at a small bookstore. You have a list of book titles and want to find out how many letters each title has. This helps you decide how much space each title will take on the shelf labels.

🎯 Goal: Build a small program that creates a list of book titles, then uses str.len() to find the length of each title. Finally, display the lengths alongside the titles.

📋 What You'll Learn

Create a pandas DataFrame with a column named Title containing the exact book titles.

Create a variable called title_lengths that stores the length of each title using str.len().

Add a new column called Length to the DataFrame using title_lengths.

Print the DataFrame to show the book titles alongside their lengths.

💡 Why This Matters

🌍 Real World

Bookstores and libraries often need to manage book titles and labels. Knowing the length of titles helps in designing labels and organizing shelves.

💼 Career

Data analysts and data scientists use string operations like <code>str.len()</code> to clean and analyze text data in many industries, including retail and publishing.

1

Create the DataFrame with book titles

Create a pandas DataFrame called books with a column named Title containing these exact book titles: 'The Great Gatsby', '1984', 'To Kill a Mockingbird', 'Pride and Prejudice', 'Moby-Dick'.

Pandas

# Create the DataFrame called books with the Title column
# Your code here

Need a hint?

Use pd.DataFrame with a dictionary where the key is 'Title' and the value is the list of book titles.

2

Create a variable to hold the lengths of each title

Create a variable called title_lengths that uses books['Title'].str.len() to find the length of each book title.

Pandas

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Great Gatsby', '1984', 'To Kill a Mockingbird', 'Pride and Prejudice', 'Moby-Dick']
})

# Create title_lengths using str.len()
# Your code here

Need a hint?

Use str.len() on the Title column to get the length of each string.

3

Add the lengths as a new column in the DataFrame

Add a new column to the books DataFrame called Length and set it equal to the title_lengths variable.

Pandas

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Great Gatsby', '1984', 'To Kill a Mockingbird', 'Pride and Prejudice', 'Moby-Dick']
})

title_lengths = books['Title'].str.len()

# Add Length column to books DataFrame
# Your code here

Need a hint?

Assign the title_lengths Series to a new column Length in the books DataFrame.

4

Print the DataFrame with titles and their lengths

Print the books DataFrame to display the book titles alongside their lengths.

Pandas

import pandas as pd

books = pd.DataFrame({
    'Title': ['The Great Gatsby', '1984', 'To Kill a Mockingbird', 'Pride and Prejudice', 'Moby-Dick']
})

title_lengths = books['Title'].str.len()

books['Length'] = title_lengths

# Print the books DataFrame
# Your code here

Need a hint?

Use print(books) to show the DataFrame with the new Length column.