Summary  
This chapter explains how to use Python’s tuple `index()` method to locate the first occurrence of a specified element and return its position, raising a `ValueError` if the element is not found.

General domain of usage  
Media library management

The `index()` method in Python is used to find the **first occurrence** of a specified element in a tuple. It returns the index of the element, which is helpful when you need to locate the position of specific data.
``` python
tuple_name.index(value)
```
The method returns the first index where the element is found.
If the element is not present in the tuple, a `ValueError` is raised.

# Tuple of movies
movies = ("Inception", "Interstellar", "Tenet", "Dunkirk", "Memento")

# Find the index of "Tenet"
tenet_index = movies.index("Tenet")

print(f"'Tenet' is at index {tenet_index}.")

The result, `2`, indicates that `"Tenet"` is the third element (since indexing starts at `0`).

import unittest
import importlib
import re

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

class TestUserCode(unittest.TestCase):

    def test_drama_movies_is_declared(self):
        import user_code
        _dynamic_test(
            self,
            hasattr(user_code, 'drama_movies'),
            "The `drama_movies` tuple is declared.",
            "Expected `drama_movies` to be declared."
        )

    def test_drama_movies_is_tuple(self):
        import user_code
        _dynamic_test(
            self,
            isinstance(user_code.drama_movies, tuple),
            "The `drama_movies` variable is of type `tuple`.",
            "Expected `drama_movies` to be of type `tuple`."
        )

    def test_fight_club_index_is_declared(self):
        import user_code
        _dynamic_test(
            self,
            hasattr(user_code, 'fight_club_index'),
            "The `fight_club_index` variable is declared.",
            "Expected `fight_club_index` to be declared."
        )

    def test_fight_club_index_is_correct(self):
        import user_code
        expected_index = user_code.drama_movies.index('Fight Club')
        _dynamic_test(
            self,
            user_code.fight_club_index == expected_index,
            f"The `fight_club_index` is `{expected_index}`.",
            f"Expected `fight_club_index` to be `{expected_index}`, but got `{user_code.fight_club_index}`."
        )

    def test_index_method_used(self):
        with open('user_code.py', 'r') as file:
            user_code_source = file.read()
        _dynamic_test(
            self,
            re.search(r'index\(', user_code_source),
            "The `index()` method is used to find the index of 'Fight Club'.",
            "Expected the `index()` method to be used."
        )

if __name__ == '__main__':
    unittest.main()


test_main.py

In this course, you'll get to know the fundamental data structures of the Python programming language. We'll explore utilizing Python's native data structures like lists, dictionaries, tuples, and sets to tackle different challenges.

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

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.

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.

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.

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

Solution

Awesome!

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

Solution

Awesome!