Lists

A list is a collection data type in Python used to store multiple items in a single variable.
Lists are ordered, changeable (mutable), and allow duplicate values.

Lists are one of the most commonly used data structures in Python.

CREATING A LIST

Lists are created using square brackets [ ].

numbers = [1, 2, 3, 4, 5]

Lists can store different data types:

mixed = [10, "Python", 3.14, True]

ACCESSING LIST ELEMENTS

List items are accessed using indexing.
Indexing starts from 0.

fruits = ["Apple", "Banana", "Mango"]print(fruits[0])   # Apple
print(fruits[1]) # Banana

Negative indexing is also allowed:

print(fruits[-1])  # Mango

SLICING A LIST

Slicing allows you to get a range of elements.

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

MODIFYING LIST ELEMENTS

Lists are mutable, meaning you can change their values.

fruits = ["Apple", "Banana", "Mango"]
fruits[1] = "Orange"print(fruits)

ADDING ELEMENTS TO A LIST

append() – Adds item at the end

numbers = [1, 2, 3]
numbers.append(4)

insert() – Adds item at specific position

numbers.insert(1, 10)

extend() – Adds multiple items

numbers.extend([5, 6])

REMOVING ELEMENTS FROM A LIST

remove() – Removes specific value

numbers.remove(10)

pop() – Removes item by index

numbers.pop(0)

clear() – Removes all items

numbers.clear()

LOOPING THROUGH A LIST

fruits = ["Apple", "Banana", "Mango"]for fruit in fruits:
print(fruit)

COMMON LIST FUNCTIONS

numbers = [5, 2, 8, 1]print(len(numbers))      # Length
print(max(numbers)) # Maximum value
print(min(numbers)) # Minimum valuenumbers.sort() # Sort list
numbers.reverse() # Reverse list

LIST COMPREHENSION

A shorter way to create lists.

squares = [x * x for x in range(5)]
print(squares)

IMPORTANT POINTS

β€’ Lists are ordered and indexed
β€’ Lists are mutable (can be changed)
β€’ Allow duplicate values
β€’ Can store multiple data types

WHY LISTS ARE IMPORTANT

β€’ Store multiple values efficiently
β€’ Useful in data processing
β€’ Essential for loops and functions
β€’ Widely used in real-world Python applications

Understanding lists is fundamental for working with data in Python.

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