Python Data Structures

Accessing Elements in a Tuple: Indexing Technique

Accessing elements in a tuple is straightforward and works the same way as with lists. Simply specify the index number inside square brackets. Remember, indexing starts at 0, just like with lists.

movies = ("Inception", "Interstellar", "The Dark Knight", "Tenet", "Dunkirk", "Memento", "Following")

# Accessing the second movie

print(movies[1])

# Accessing the sixth movie

print(movies[5])


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movies = ("Inception", "Interstellar", "The Dark Knight", "Tenet", "Dunkirk", "Memento", "Following")

# Accessing the second movie
print(movies[1])

# Accessing the sixth movie
print(movies[5])

Tuples also support negative indexing, where the indexing begins from the end. Thus, the last element has an index of -1, the second to last is -2, and so on.

movies = ("Inception", "Interstellar", "The Dark Knight", "Tenet", "Dunkirk", "Memento", "Following")

# Accessing the last movie

print(movies[-1])

# Accessing the fourth movie from the end

print(movies[-4])


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movies = ("Inception", "Interstellar", "The Dark Knight", "Tenet", "Dunkirk", "Memento", "Following")

# Accessing the last movie
print(movies[-1])

# Accessing the fourth movie from the end
print(movies[-4])

In the example above, we access the last element (indexed at -1) and the fourth element from the end (indexed at -4).

Task

Swipe to start coding

We are continuing to work with the tuple space_movies.

Get the first element of this tuple and store it in the variable first_movie.
Get the last element of the tuple and store it in the variable last_movie.
Initialize a new list favorite_movies and add these 2 movies to it.
Use indices to complete this task.

Solution

space_movies = ('2001: A Space Odyssey', 'Interstellar', 'Star Wars: Episode IV - A New Hope', 'Gravity', 'The Martian')

# Write your code here

first_movie = space_movies[0]

last_movie = space_movies[-1]

favorite_movies = [first_movie, last_movie]

# Testing

print("Favorite movies about space:", favorite_movies)

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 2

space_movies = ('2001: A Space Odyssey', 'Interstellar', 'Star Wars: Episode IV - A New Hope', 'Gravity', 'The Martian')

# Write your code here

first_movie = ___

last_movie = ___

favorite_movies = ___

# Testing

print("Favorite movies about space:", favorite_movies)

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Python Data Structures

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1. Mastering Python Lists

What is a list? A list is an ordered collection that can be modified. It also allows for duplicate elements.

Creating Lists in Python: Declaring and Initializing Lists

List Indexing in Python: Accessing Elements Efficiently

Working with Nested Lists in Python

Python List Length: Measuring and Managing List Size

Modifying Lists in Python: Updating and Changing Elements

Using the append() Method: Adding Elements to Lists

Using the insert() Method: Placing Elements at Specific Positions

Deleting Elements in Python Lists: Removing Items Safely

Using the remove() Method: Deleting Specific Elements from Lists

2. Mastering Python Dictionaries

What is a dictionary? A dictionary is an ordered collection that can be changed, but it doesn't allow duplicate entries. It consists of `key:value` pairs, which are used to optimize its structure.

Creating a Dictionary in Python: Storing Key-Value Pairs

Accessing Dictionary Values

Accessing Dictionary Keys

Adding Items to a Dictionary: Updating Key-Value Pairs

Using the del Keyword: Removing Dictionary Entries

Using the pop() Method: Deleting Elements with Return Values

Using the popitem() Method: Removing the Last Inserted Item

Using the clear() Method: Emptying a Dictionary Completely

3. Mastering Python Tuples

What is a tuple? A tuple is an ordered collection that cannot be altered. It can have duplicate elements. While it's similar to a list, the values in a tuple can be of any type and are indexed by integers. Although not mandatory, it's common to enclose the values of a tuple in parentheses, making them easier to understand in Python.

Creating a Tuple in Python: Defining Immutable Data Structures

Accessing Elements in a Tuple: Indexing Technique

Concatenating Tuples in Python: Merging Immutable Sequences

Deleting Tuples in Python: Removing References to Tuples

Updating Tuples in Python

Adding Items to a Tuple: Alternative Approaches Using Lists

Counting Elements in a Tuple: Using the count() Method

Finding Elements in a Tuple: Using the index() Method for Lookup

4. Mastering Python Sets

What is a set? In Python, a `set` is an unordered collection that is both `iterable` and `mutable`, with no repeated elements. While the order of items in a set isn't fixed, it can include a variety of elements. A key benefit of using sets over lists is their highly efficient method for determining if an element exists within the set.

Creating a Set in Python: Defining Unordered Collections

Using the add() Method: Adding Single Elements to a Set

Using the update() Method: Merging Multiple Elements into a Set

Accessing Elements in a Set: Iteration and Membership Testing

Using the remove() and discard() Methods

Using the clear() Method: Removing All Elements from a Set