**Course Title:** Modern Python Programming: Best Practices and Trends **Section Title:** Data Structures and Basic Algorithms **Topic:** Implement data manipulation tasks using lists, dictionaries, and comprehensions.(Lab topic) **Objective:** In this lab, you will learn how to implement data manipulation tasks using lists, dictionaries, and comprehensions. By the end of this topic, you will be able to write efficient and effective code to manipulate data in Python. **Manipulating Data with Lists** Lists are a fundamental data structure in Python, and they provide several methods for manipulating data. Here are some common methods: * **Indexing and Slicing:** Lists are indexed, which means you can access individual elements using their index. You can also slice lists to get a subset of elements. ```python # Create a list numbers = [1, 2, 3, 4, 5] # Access the first element print(numbers[0]) # Output: 1 # Slice the list to get the first three elements print(numbers[:3]) # Output: [1, 2, 3] ``` * **Append and Extend:** You can add elements to the end of a list using the `append` method or add multiple elements using the `extend` method. ```python # Create a list numbers = [1, 2, 3] # Append an element numbers.append(4) print(numbers) # Output: [1, 2, 3, 4] # Extend the list with multiple elements numbers.extend([5, 6, 7]) print(numbers) # Output: [1, 2, 3, 4, 5, 6, 7] ``` * **Insert and Remove:** You can insert an element at a specific index using the `insert` method or remove an element using the `remove` method. ```python # Create a list numbers = [1, 2, 3] # Insert an element at the beginning numbers.insert(0, 0) print(numbers) # Output: [0, 1, 2, 3] # Remove the first element numbers.remove(0) print(numbers) # Output: [1, 2, 3] ``` **Manipulating Data with Dictionaries** Dictionaries are another fundamental data structure in Python, and they provide several methods for manipulating data. Here are some common methods: * **Key-Value Pairs:** Dictionaries store data as key-value pairs. You can access a value by its key. ```python # Create a dictionary person = {"name": "John", "age": 30} # Access a value by its key print(person["name"]) # Output: John ``` * **Update and Delete:** You can update a value by its key or delete a key-value pair. ```python # Create a dictionary person = {"name": "John", "age": 30} # Update a value by its key person["age"] = 31 print(person) # Output: {"name": "John", "age": 31} # Delete a key-value pair del person["age"] print(person) # Output: {"name": "John"} ``` **Manipulating Data with Comprehensions** Comprehensions provide a concise way to create lists, dictionaries, and sets from existing data structures. Here are some common uses: * **List Comprehensions:** You can create a new list from an existing list or other data structure. ```python # Create a list numbers = [1, 2, 3, 4, 5] # Create a new list with squared numbers squared_numbers = [num ** 2 for num in numbers] print(squared_numbers) # Output: [1, 4, 9, 16, 25] ``` * **Dictionary Comprehensions:** You can create a new dictionary from an existing dictionary or other data structure. ```python # Create a dictionary person = {"name": "John", "age": 30} # Create a new dictionary with the same keys and values doubled doubled_person = {key: value * 2 for key, value in person.items()} print(doubled_person) # Output: {"name": "JohnJohn", "age": 60} ``` **Practical Takeaways** * Use lists to store ordered data and manipulate it using indexing, slicing, appending, and removing. * Use dictionaries to store key-value pairs and manipulate it using key access, updating, and deleting. * Use comprehensions to create new lists, dictionaries, and sets from existing data structures. **Lab Exercise** Complete the following exercises to practice manipulating data with lists, dictionaries, and comprehensions: 1. Create a list of numbers and use indexing and slicing to access and manipulate its elements. 2. Create a dictionary with personal data and use key access and updating to manipulate its values. 3. Create a new list using a list comprehension and experiment with different operations. 4. Create a new dictionary using a dictionary comprehension and experiment with different operations. **Additional Resources** * [Official Python documentation on lists](https://docs.python.org/3/tutorial/datastructures.html) * [Official Python documentation on dictionaries](https://docs.python.org/3/tutorial/datastructures.html) * [Official Python documentation on comprehensions](https://docs.python.org/3/tutorial/datastructures.html) **Do you have any questions about this topic? Please leave a comment below or ask for help.** In the next topic, we will cover 'Defining and using functions: Arguments, return values, and scope.' This topic will explore how to write reusable and modular code using functions, which are a fundamental building block of programming. We will cover the basics of function definitions, function calls, and function scope.