Python Basics: Lists, Tuples, and Sets

One of the many reasons behind Python's popularity is its in-built data structures, which help developers store and organize data efficiently. Below we are exploring three fundamental data structures in Python:

• lists - mutable ordered collection
• tuples - immutable ordered collection
• sets - mutable unordered collection of unique elements

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Lists

A list is a mutable, ordered collection of elements in Python. It can store elements of different data types, including integers, strings, and even other lists.

Creating a List

To create a list, you can use square brackets [] and separate the elements with commas. For example:

fruits = ['apple', 'banana', 'cherry']
numbers = [1, 2, 3, 4, 5]

List Methods and Operations

Accessing elements: You can access elements in a list using their index, starting with 0 for the first element:

fruits = ['apple', 'banana', 'cherry']
print(fruits[1])  # Output: banana

Adding elements: To add elements to a list, you can use the append() method:

fruits = ['apple', 'banana', 'cherry']
fruits.append('orange')
print(fruits)  # Output: ['apple', 'banana', 'cherry', 'orange']

Removing elements: To remove elements from a list, use the remove() method:

fruits = ['apple', 'banana', 'cherry']
fruits.remove('banana')
print(fruits)  # Output: ['apple', 'cherry']

Slicing: You can extract a portion of a list by specifying the start and end indices:

numbers = [1, 2, 3, 4, 5]
sliced_numbers = numbers[1:4]
print(sliced_numbers)  # Output: [2, 3, 4]

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Tuples

A tuple is an immutable, ordered collection of elements in Python. Once a tuple is created, you cannot modify its contents.

Creating a Tuple

To create a tuple, use parentheses () and separate the elements with commas:

fruits = ('apple', 'banana', 'cherry')
coordinates = (3, 4, 5)

Tuple Methods and Operations

Accessing elements: Accessing elements in a tuple is the same as in a list:

fruits = ('apple', 'banana', 'cherry')
print(fruits[1])  # Output: banana

Counting elements: To count the occurrences of an element in a tuple, use the count() method:

numbers = (1, 2, 3, 2, 4, 2)
count_of_twos = numbers.count(2)
print(count_of_twos)  # Output: 3

Finding the index: To find the index of the first occurrence of an element, use the index() method:

fruits = ('apple', 'banana', 'cherry')
index_of_banana = fruits.index('banana')
print(index_of_banana)  # Output: 1

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Sets

A set is an unordered, mutable collection of unique elements in Python. Sets do not allow duplicate elements.

Creating a Set

To create a set, use curly braces {} and separate the elements with commas, or use the set() constructor:

fruits = {'apple', 'banana', 'cherry'}
numbers = set([1, 2, 3, 4, 5])

Set Methods and Operations

Adding elements: To add elements to a set, use the add() method:

fruits = {'apple', 'banana', 'cherry'}
fruits.add('orange')
print(fruits)  # Output: {'apple', 'banana', 'cherry', 'orange'}

Removing elements: To remove elements from a set, use the remove() method:

fruits = {'apple', 'banana', 'cherry'}
fruits.remove('banana')
print(fruits)  # Output: {'apple', 'cherry'}

Union: To combine two sets, use the union() method or the | operator:

set1 = {1, 2, 3}
set2 = {3, 4, 5}
union_set = set1.union(set2)
# or
union_set = set1 | set2
print(union_set)  # Output: {1, 2, 3, 4, 5}

Intersection: To find the common elements between two sets, use the intersection() method or the & operator:

set1 = {1, 2, 3}
set2 = {3, 4, 5}
intersection_set = set1.intersection(set2)
# or
intersection_set = set1 & set2
print(intersection_set)  # Output: {3}

Difference: To find the elements present in one set but not in another, use the difference() method or the - operator:

set1 = {1, 2, 3}
set2 = {3, 4, 5}
difference_set = set1.difference(set2)
# or
difference_set = set1 - set2
print(difference_set)  # Output: {1, 2}