23. Python Lists

Create List

fruits = ["apple", "banana", "mango"]

print(fruits)

Output

['apple', 'banana', 'mango']

Explanation Lists store ordered, mutable collections.

Access List Items

print(fruits[0])

Output

apple

Explanation Access items using indexes.

Change List Items

fruits[1] = "orange"

print(fruits)

Output

['apple', 'orange', 'mango']

Explanation Modify items using indexes.

Add List Items

fruits.append("grapes")

print(fruits)

Output

['apple', 'banana', 'mango', 'grapes']

Explanation append() adds an item to the end.

Remove List Items

fruits.remove("banana")

print(fruits)

Output

['apple', 'mango']

Explanation remove() deletes a specified item.

Loop Lists

for fruit in fruits:
    print(fruit)

Output

apple
banana
mango

Explanation Iterate through each item in the list.

List Comprehension

numbers = [x * 2 for x in range(5)]

print(numbers)

Output

[0, 2, 4, 6, 8]

Explanation Create lists using a concise syntax.

Sort Lists

numbers = [5, 2, 4]

numbers.sort()

print(numbers)

Output

[2, 4, 5]

Explanation Sort items in ascending order.

Copy Lists

list1 = [1, 2, 3]
list2 = list1.copy()

print(list2)

Output

[1, 2, 3]

Explanation Create a separate copy of a list.

Join Lists

a = [1, 2]
b = [3, 4]

print(a + b)

Output

[1, 2, 3, 4]

Explanation Combine two lists.

Common List Methods

Method	Purpose
`append()`	Add item at end
`insert()`	Insert at position
`extend()`	Add another iterable
`remove()`	Remove specific item
`pop()`	Remove by index
`clear()`	Remove all items
`copy()`	Copy list
`sort()`	Sort list
`reverse()`	Reverse list
`count()`	Count occurrences
`index()`	Find position

24. Python Tuples

24.1 Create Tuple

colors = ("red", "green", "blue")

print(colors)

Output

('red', 'green', 'blue')

Explanation: A tuple stores multiple ordered items.

24.2 Tuple Length

colors = ("red", "green", "blue")

print(len(colors))

Output

Explanation: len() returns the number of items in a tuple.

24.3 Create Tuple With One Item

fruit = ("apple",)

print(type(fruit))

Output

<class 'tuple'>

Explanation: A single-item tuple must end with a comma.

24.4 Tuple Data Types

numbers = (1, 2, 3)
names = ("John", "Sam")
mixed = (1, "Python", True)

print(numbers)
print(names)
print(mixed)

Output

(1, 2, 3)
('John', 'Sam')
(1, 'Python', True)

Explanation: Tuples can store different data types.

24.5 Access Tuple Items

colors = ("red", "green", "blue")

print(colors[1])

Output

green

Explanation: Access tuple items using indexes.

24.6 Negative Indexing

colors = ("red", "green", "blue")

print(colors[-1])

Output

blue

Explanation: Negative indexes start from the end.

24.7 Range of Indexes

colors = ("red", "green", "blue", "yellow")

print(colors[1:3])

Output

('green', 'blue')

Explanation: Slice returns a portion of the tuple.

24.8 Check if Item Exists

colors = ("red", "green", "blue")

print("green" in colors)

Output

True

Explanation: in checks whether an item exists.

24.9 Change Tuple Items

colors = ("red", "green", "blue")

temp = list(colors)
temp[1] = "black"
colors = tuple(temp)

print(colors)

Output

('red', 'black', 'blue')

Explanation: Convert to a list to modify tuple items.

24.10 Add Items

colors = ("red", "green")

colors += ("blue",)

print(colors)

Output

('red', 'green', 'blue')

Explanation: Tuples are immutable, so create a new tuple.

24.11 Remove Items

colors = ("red", "green", "blue")

temp = list(colors)
temp.remove("green")
colors = tuple(temp)

print(colors)

Output

('red', 'blue')

Explanation: Convert to a list to remove items.

24.12 Unpack Tuples

colors = ("red", "green", "blue")

a, b, c = colors

print(a)
print(b)
print(c)

Output

red
green
blue

Explanation: Assign tuple values to separate variables.

24.13 Using Asterisk (*)

colors = ("red", "green", "blue", "yellow")

a, *b = colors

print(a)
print(b)

Output

red
['green', 'blue', 'yellow']

Explanation: * collects remaining values into a list.

24.14 Loop Through Tuple

colors = ("red", "green", "blue")

for color in colors:
    print(color)

Output

red
green
blue

Explanation: Loop through tuple items using for.

24.15 Join Tuples

tuple1 = (1, 2)
tuple2 = (3, 4)

print(tuple1 + tuple2)

Output

(1, 2, 3, 4)

Explanation: + joins two tuples.

24.16 Multiply Tuples

numbers = (1, 2)

print(numbers * 3)

Output

(1, 2, 1, 2, 1, 2)

Explanation: * repeats tuple elements.

24.17 Tuple Methods

count()

numbers = (1, 2, 2, 3)

print(numbers.count(2))

Output

Explanation: Counts occurrences of an item.

index()

numbers = (1, 2, 3)

print(numbers.index(2))

Output

Explanation: Returns the index of the first occurrence.

25. Python Sets

25.1 Create Set

fruits = {"apple", "banana", "mango"}

print(fruits)

Output

{'apple', 'banana', 'mango'}

Explanation: Sets store unordered unique items.

25.2 Set Length

fruits = {"apple", "banana", "mango"}

print(len(fruits))

Output

Explanation: Returns the number of items.

25.3 Duplicate Values

numbers = {1, 2, 2, 3}

print(numbers)

Output

{1, 2, 3}

Explanation: Duplicate values are removed automatically.

25.4 Access Set Items

fruits = {"apple", "banana", "mango"}

for item in fruits:
    print(item)

Output

apple
banana
mango

Explanation: Sets do not support indexing.

25.5 Check Item Exists

fruits = {"apple", "banana"}

print("banana" in fruits)

Output

True

Explanation: in checks item existence.

25.6 Add Items

fruits = {"apple"}

fruits.add("banana")

print(fruits)

Output

{'apple', 'banana'}

Explanation: add() inserts one item.

25.7 Add Multiple Items

fruits = {"apple"}

fruits.update(["banana", "mango"])

print(fruits)

Output

{'apple', 'banana', 'mango'}

Explanation: update() adds multiple items.

25.8 Remove Item

fruits = {"apple", "banana"}

fruits.remove("banana")

print(fruits)

Output

{'apple'}

Explanation: remove() deletes an item.

25.9 discard()

fruits = {"apple", "banana"}

fruits.discard("orange")

print(fruits)

Output

{'apple', 'banana'}

Explanation: discard() doesn’t raise an error if the item doesn’t exist.

25.10 pop()

fruits = {"apple", "banana"}

fruits.pop()

print(fruits)

Output

{'banana'}

Explanation: Removes a random item.

25.11 clear()

fruits = {"apple", "banana"}

fruits.clear()

print(fruits)

Output

set()

Explanation: Removes all items.

25.12 Loop Set

fruits = {"apple", "banana"}

for fruit in fruits:
    print(fruit)

Output

apple
banana

Explanation: Iterate through every item.

25.13 Join Sets (Union)

a = {1, 2}
b = {3, 4}

print(a.union(b))

Output

{1, 2, 3, 4}

Explanation: Combines all unique elements.

25.14 Intersection

a = {1, 2, 3}
b = {2, 3, 4}

print(a.intersection(b))

Output

{2, 3}

Explanation: Returns common items.

25.15 Difference

a = {1, 2, 3}
b = {2, 3}

print(a.difference(b))

Output

{1}

Explanation: Returns items only in the first set.

Common Set Methods

Method	Purpose
add()	Add one item
update()	Add multiple items
remove()	Remove item
discard()	Remove safely
pop()	Remove random item
clear()	Remove all items
union()	Join sets
intersection()	Common elements
difference()	Different elements
copy()	Copy set

26. Python Dictionaries

26.1 Create Dictionary

student = {
    "name": "John",
    "age": 20
}

print(student)

Output

{'name': 'John', 'age': 20}

Explanation: Dictionaries store data as key-value pairs.

26.2 Dictionary Length

student = {
    "name": "John",
    "age": 20
}

print(len(student))

Output

Explanation: Returns the number of key-value pairs.

26.3 Access Items

student = {
    "name": "John",
    "age": 20
}

print(student["name"])

Output

John

Explanation: Access values using keys.

26.4 get()

student = {
    "name": "John"
}

print(student.get("name"))

Output

John

Explanation: get() safely returns a value.

26.5 keys()

student = {
    "name": "John",
    "age": 20
}

print(student.keys())

Output

dict_keys(['name', 'age'])

Explanation: Returns all keys.

26.6 values()

student = {
    "name": "John",
    "age": 20
}

print(student.values())

Output

dict_values(['John', 20])

Explanation: Returns all values.

26.7 items()

student = {
    "name": "John",
    "age": 20
}

print(student.items())

Output

dict_items([('name', 'John'), ('age', 20)])

Explanation: Returns key-value pairs.

26.8 Change Items

student = {
    "name": "John",
    "age": 20
}

student["age"] = 21

print(student)

Output

{'name': 'John', 'age': 21}

Explanation: Change a value using its key.

26.9 update()

student = {
    "name": "John"
}

student.update({"age": 20})

print(student)

Output

{'name': 'John', 'age': 20}

Explanation: Adds or updates key-value pairs.

26.10 Add Items

student = {
    "name": "John"
}

student["city"] = "Chennai"

print(student)

Output

{'name': 'John', 'city': 'Chennai'}

Explanation: Assign a new key to add an item.

26.11 Remove Items

pop()

student = {
    "name": "John",
    "age": 20
}

student.pop("age")

print(student)

Output

{'name': 'John'}

Explanation: Removes a specified key.

popitem()

student = {
    "name": "John",
    "age": 20
}

student.popitem()

print(student)

Output

{'name': 'John'}

Explanation: Removes the last inserted item.

del

student = {
    "name": "John",
    "age": 20
}

del student["age"]

print(student)

Output

{'name': 'John'}

Explanation: Deletes a key-value pair.

clear()

student = {
    "name": "John",
    "age": 20
}

student.clear()

print(student)

Output

{}

Explanation: Removes all items.

26.12 Loop Dictionaries

student = {
    "name": "John",
    "age": 20
}

for key, value in student.items():
    print(key, value)

Output

name John
age 20

Explanation: Iterate through keys and values.

26.13 Copy Dictionary

student = {
    "name": "John"
}

copy_dict = student.copy()

print(copy_dict)

Output

{'name': 'John'}

Explanation: Creates a separate copy of the dictionary.

26.14 Nested Dictionaries

students = {
    "student1": {
        "name": "John",
        "age": 20
    },
    "student2": {
        "name": "Alice",
        "age": 21
    }
}

print(students["student1"]["name"])

Output

John

Explanation: A dictionary can contain other dictionaries.

Common Dictionary Methods

Method	Purpose
get()	Get value safely
keys()	Return all keys
values()	Return all values
items()	Return key-value pairs
update()	Add/update items
pop()	Remove by key
popitem()	Remove last item
clear()	Remove all items
copy()	Copy dictionary
setdefault()	Return value or insert default

​23. Python Lists

​Create List

​Access List Items

​Change List Items

​Add List Items

​Remove List Items

​Loop Lists

​List Comprehension

​Sort Lists

​Copy Lists

​Join Lists

​Common List Methods

​24. Python Tuples

​24.1 Create Tuple

​Output

​24.2 Tuple Length

​Output

​24.3 Create Tuple With One Item

​Output

​24.4 Tuple Data Types

​Output

​24.5 Access Tuple Items

​Output

​24.6 Negative Indexing

​Output

​24.7 Range of Indexes

​Output

​24.8 Check if Item Exists

​Output

​24.9 Change Tuple Items

​Output

​24.10 Add Items

​Output

​24.11 Remove Items

​Output

​24.12 Unpack Tuples

​Output

​24.13 Using Asterisk (*)

​Output

​24.14 Loop Through Tuple

​Output

​24.15 Join Tuples

​Output

​24.16 Multiply Tuples

​Output

​24.17 Tuple Methods

​count()

​index()

​25. Python Sets

​25.1 Create Set

​Output

​25.2 Set Length

​Output

​25.3 Duplicate Values

​Output

​25.4 Access Set Items

​Output

​25.5 Check Item Exists

​Output

​25.6 Add Items

​Output

​25.7 Add Multiple Items

​Output

​25.8 Remove Item

​Output

​25.9 discard()

​Output

​25.10 pop()

​Output

​25.11 clear()

​Output

​25.12 Loop Set

​Output

​25.13 Join Sets (Union)

​Output

​25.14 Intersection

​Output

​25.15 Difference

​Output

​Common Set Methods

23. Python Lists

Create List

Access List Items

Change List Items

Add List Items

Remove List Items

Loop Lists

List Comprehension

Sort Lists

Copy Lists

Join Lists

Common List Methods

24. Python Tuples

24.1 Create Tuple

Output

24.2 Tuple Length

Output

24.3 Create Tuple With One Item

Output

24.4 Tuple Data Types

Output

24.5 Access Tuple Items

Output

24.6 Negative Indexing

Output

24.7 Range of Indexes

Output

24.8 Check if Item Exists

Output

24.9 Change Tuple Items

Output

24.10 Add Items

Output

24.11 Remove Items

Output

24.12 Unpack Tuples

Output

24.13 Using Asterisk (*)

Output

24.14 Loop Through Tuple

Output

24.15 Join Tuples

Output

24.16 Multiply Tuples

Output

24.17 Tuple Methods

count()

index()

25. Python Sets

25.1 Create Set

Output

25.2 Set Length

Output

25.3 Duplicate Values

Output

25.4 Access Set Items

Output

25.5 Check Item Exists

Output

25.6 Add Items

Output

25.7 Add Multiple Items

Output

25.8 Remove Item

Output

25.9 discard()

Output

25.10 pop()

Output

25.11 clear()

Output

25.12 Loop Set

Output

25.13 Join Sets (Union)

Output

25.14 Intersection

Output

25.15 Difference

Output

Common Set Methods