String values and text handling in Python - Mini Project: Build & Apply

String values and text handling

📖 Scenario: You are working on a simple program that manages a list of book titles in a small library. You want to practice handling string values and text operations in Python.

🎯 Goal: Build a program that stores book titles, sets a keyword to search for, finds all titles containing that keyword, and prints the matching titles.

📋 What You'll Learn

Create a list of book titles with exact given values

Create a keyword variable with a specific string

Use a list comprehension to find titles containing the keyword

Print the list of matching titles

💡 Why This Matters

🌍 Real World

Managing and searching text data like book titles, product names, or messages is common in many software applications.

💼 Career

Understanding string handling and filtering is important for roles in data processing, software development, and quality assurance.

1

Create the list of book titles

Create a list called books with these exact titles: 'The Great Gatsby', 'To Kill a Mockingbird', 'Great Expectations', 'The Catcher in the Rye', and 'The Grapes of Wrath'.

Python

# Create the list of book titles
# Your code here

Hint

Use square brackets [] to create a list and separate each title with commas.

2

Set the keyword to search

Create a variable called keyword and set it to the string 'Great'.

Python

books = ['The Great Gatsby', 'To Kill a Mockingbird', 'Great Expectations', 'The Catcher in the Rye', 'The Grapes of Wrath']
# Create the keyword variable
# Your code here

Hint

Use simple assignment with the exact string 'Great'.

3

Find titles containing the keyword

Use a list comprehension to create a new list called matching_books that includes only the titles from books that contain the keyword string.

Python

books = ['The Great Gatsby', 'To Kill a Mockingbird', 'Great Expectations', 'The Catcher in the Rye', 'The Grapes of Wrath']
keyword = 'Great'
# Create matching_books list using list comprehension
# Your code here

Hint

Use [title for title in books if keyword in title] to filter titles containing the keyword.

4

Print the matching titles

Print the matching_books list to show the titles that contain the keyword.

Python

books = ['The Great Gatsby', 'To Kill a Mockingbird', 'Great Expectations', 'The Catcher in the Rye', 'The Grapes of Wrath']
keyword = 'Great'
matching_books = [title for title in books if keyword in title]
# Print the matching_books list
# Your code here

Hint

Use print(matching_books) to display the list.

Practice

1. What is the correct way to create a string in Python?

easy

A. Using quotes like "Hello" or 'Hello'

B. Using parentheses like (Hello)

C. Using curly braces like {Hello}

D. Using square brackets like [Hello]

Solution

1. Step 1: Understand string syntax in Python

   Strings are text and must be enclosed in quotes, either single or double.

2. Step 2: Check each option

   Only Using quotes like "Hello" or 'Hello' uses quotes correctly. Parentheses, curly braces, and square brackets are for other data types.

3. Final Answer:

   Using quotes like "Hello" or 'Hello' -> Option A

4. Quick Check:

   Strings need quotes = C [OK]

Hint: Remember: strings always need quotes around text [OK]

Common Mistakes:

• Using parentheses instead of quotes
• Confusing brackets with quotes
• Forgetting to close quotes

2. Which of the following is the correct syntax to create a multi-line string in Python?

easy

A. '''This is a multi-line string'''

B. "This is a multi-line string"

C. 'This is a multi-line string'

D. --This is a multi-line string--

Solution

1. Step 1: Recall multi-line string syntax

   Python uses triple quotes (either ''' or """) to create strings that span multiple lines.

2. Step 2: Evaluate options

   '''This is a multi-line string''' uses triple single quotes correctly. Options B and C use single or double quotes for single-line strings. --This is a multi-line string-- is invalid syntax.

3. Final Answer:

   '''This is a multi-line string''' -> Option A

4. Quick Check:

   Triple quotes = multi-line string [OK]

Hint: Use triple quotes for multi-line strings [OK]

Common Mistakes:

• Using single or double quotes for multi-line text
• Using invalid symbols like --
• Not closing triple quotes properly

3. What will be the output of the following code?

text = "Hello World"
print(text[6:])

medium

A. Hello

B. World

C. World!

D. Hello World

Solution

1. Step 1: Understand string slicing

   text[6:] means start from index 6 to the end of the string. Indexing starts at 0.

2. Step 2: Identify substring from index 6

   In "Hello World", index 6 is 'W', so text[6:] is "World".

3. Final Answer:

   World -> Option B

4. Quick Check:

   text[6:] = World [OK]

Hint: Remember string index starts at 0; slice from index 6 to end [OK]

Common Mistakes:

• Confusing index start point
• Including extra characters like '!'
• Printing entire string instead of slice

4. Find the error in this code snippet:

name = 'Alice
print(name)

medium

A. Incorrect use of newline character

B. print() function is misspelled

C. Missing closing quote for the string

D. Variable name is invalid

Solution

1. Step 1: Check string syntax

   The string starts with a single quote but does not have a closing quote before the newline.

2. Step 2: Identify syntax error

   Because the closing quote is missing, Python will raise a syntax error.

3. Final Answer:

   Missing closing quote for the string -> Option C

4. Quick Check:

   Unclosed string causes syntax error [OK]

Hint: Always close your quotes before newline or end [OK]

Common Mistakes:

• Forgetting to close quotes
• Thinking newline character causes error
• Assuming print is misspelled

5. You have a list of words: words = ['apple', 'banana', 'cherry']. Which code correctly joins them into a single string separated by commas?

hard

A. result = ','.join([words])

B. result = words.join(',')

C. result = ','.join('words')

D. result = ','.join(words)

Solution

1. Step 1: Understand join() method usage

   The join() method is called on the string separator and takes an iterable of strings as argument.

2. Step 2: Check each option

   result = ','.join(words) correctly calls join on the comma string with the list words. Others misuse join or pass wrong arguments.

3. Final Answer:

   result = ','.join(words) -> Option D

4. Quick Check:

   Separator.join(list) joins list items [OK]

Hint: Call join on separator string, pass list to join() [OK]

Common Mistakes:

• Calling join on the list instead of the string
• Passing string 'words' instead of list variable
• Passing list inside another list