From 4a2895919564b1a4b0cc6e42dac362c712dfb202 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Sun, 9 Aug 2026 12:30:51 +0100
Subject: [PATCH 01/13] producting  what 2 * 22 will do in py

---
 sprint5-prep-exercises/predictDouble.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 sprint5-prep-exercises/predictDouble.py

diff --git a/sprint5-prep-exercises/predictDouble.py b/sprint5-prep-exercises/predictDouble.py
new file mode 100644
index 000000000..866197dd1
--- /dev/null
+++ b/sprint5-prep-exercises/predictDouble.py
@@ -0,0 +1,13 @@
+def half(value):
+    return value / 2 
+
+def double(value):
+    return value * 2 
+
+def second(value):
+    return value[1]
+
+
+print(double("22"))
+# I predicted that it would return an error, but it actually returned 2222.
+#  I didn't expect this because I thought double() was supposed to work only with numbers.
\ No newline at end of file

From 4b082acd81b15e6d5594ad6d72ae4252cc6d5660 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Sun, 9 Aug 2026 12:43:05 +0100
Subject: [PATCH 02/13] Limits of type checking

---
 sprint5-prep-exercises/LimiOfTypeCheck.py | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 sprint5-prep-exercises/LimiOfTypeCheck.py

diff --git a/sprint5-prep-exercises/LimiOfTypeCheck.py b/sprint5-prep-exercises/LimiOfTypeCheck.py
new file mode 100644
index 000000000..9f7a5e528
--- /dev/null
+++ b/sprint5-prep-exercises/LimiOfTypeCheck.py
@@ -0,0 +1,7 @@
+def double(number):
+    # return number * 3
+    return number * 2
+
+print(double(10))
+# The bug is that the double function multiplies the number by 3 instead of 2.
+#  Since the function is called double, it should multiply the number by 2. 
\ No newline at end of file

From e437bab6decf912b75a64a95c9217ae22504a93a Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Sun, 9 Aug 2026 16:53:22 +0100
Subject: [PATCH 03/13] Running the code through mypy, and fix all of the bugs
 that show up

---
 sprint5-prep-exercises/typeAnnotations.py | 35 +++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 sprint5-prep-exercises/typeAnnotations.py

diff --git a/sprint5-prep-exercises/typeAnnotations.py b/sprint5-prep-exercises/typeAnnotations.py
new file mode 100644
index 000000000..5aeb69840
--- /dev/null
+++ b/sprint5-prep-exercises/typeAnnotations.py
@@ -0,0 +1,35 @@
+
+def open_account(balances: dict[str, int], name: str, amount: int):
+    balances[name] = amount
+
+
+def sum_balances(accounts: dict[str, int]) -> int:
+    total = 0
+    for name, pence in accounts.items():
+        print(f"{name} had balance {pence}")
+        total += pence
+    return total
+
+
+def format_pence_as_string(total_pence: int) -> str:
+    if total_pence < 100:
+        return f"{total_pence}p"
+    pounds = int(total_pence / 100)
+    pence = total_pence % 100
+    return f"£{pounds}.{pence:02d}"
+
+
+balances: dict[str, int] = {
+    "Sima": 700,
+    "Linn": 545,
+    "Georg": 831,
+}
+
+
+open_account(balances, "Tobi", 913)
+open_account(balances, "Olya", 713)
+
+total_pence = sum_balances(balances)
+total_string = format_pence_as_string(total_pence)
+
+print(f"The bank accounts total {total_string}")
\ No newline at end of file

From 8c9cd800678e6ca7b47a832df2d84a3624f6f60b Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Sun, 9 Aug 2026 17:27:14 +0100
Subject: [PATCH 04/13] understanding mypy error message

---
 sprint5-prep-exercises/classesAndObjects.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 sprint5-prep-exercises/classesAndObjects.py

diff --git a/sprint5-prep-exercises/classesAndObjects.py b/sprint5-prep-exercises/classesAndObjects.py
new file mode 100644
index 000000000..6d333ffd7
--- /dev/null
+++ b/sprint5-prep-exercises/classesAndObjects.py
@@ -0,0 +1,13 @@
+class Person:
+    def __init__(self, name: str, age: int, preferred_operating_system: str):
+        self.name = name
+        self.age = age
+        self.preferred_operating_system = preferred_operating_system
+
+imran = Person("Imran", 22, "Ubuntu")
+print(imran.name)
+print(imran.address)
+
+eliza = Person("Eliza", 34, "Arch Linux")
+print(eliza.name)
+print(eliza.address)
\ No newline at end of file

From aad3e376522e8139b2c4a0c515686ea2996231ac Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Tue, 11 Aug 2026 13:49:40 +0100
Subject: [PATCH 05/13] Change the Person class to take a date of birth

---
 sprint5-prep-exercises/accessNotExiProp.py  | 11 ++++++++++
 sprint5-prep-exercises/classesAndObjects.py |  6 +++++-
 sprint5-prep-exercises/methods.py           | 23 +++++++++++++++++++++
 sprint5-prep-exercises/typeAnnotations.py   |  6 +++++-
 4 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 sprint5-prep-exercises/accessNotExiProp.py
 create mode 100644 sprint5-prep-exercises/methods.py

diff --git a/sprint5-prep-exercises/accessNotExiProp.py b/sprint5-prep-exercises/accessNotExiProp.py
new file mode 100644
index 000000000..5be277df5
--- /dev/null
+++ b/sprint5-prep-exercises/accessNotExiProp.py
@@ -0,0 +1,11 @@
+class Person:
+    def __init__(self, name: str):
+        self.name = name
+
+def get_name(person: Person) -> str:
+    return person.name
+
+def get_age(person: Person) -> int:
+    return person.age
+# As I expected, mypy prints an error saying that Person has no attribute name,
+#  because the age property does not exist in the Person class.
\ No newline at end of file
diff --git a/sprint5-prep-exercises/classesAndObjects.py b/sprint5-prep-exercises/classesAndObjects.py
index 6d333ffd7..2cfe36f78 100644
--- a/sprint5-prep-exercises/classesAndObjects.py
+++ b/sprint5-prep-exercises/classesAndObjects.py
@@ -10,4 +10,8 @@ def __init__(self, name: str, age: int, preferred_operating_system: str):
 
 eliza = Person("Eliza", 34, "Arch Linux")
 print(eliza.name)
-print(eliza.address)
\ No newline at end of file
+print(eliza.address)
+
+
+# The error means that address doesn't exist in the Person class. We can only 
+# access attributes that were defined in the class, such as name, age, and preferred_operating_system.
\ No newline at end of file
diff --git a/sprint5-prep-exercises/methods.py b/sprint5-prep-exercises/methods.py
new file mode 100644
index 000000000..f449f9c88
--- /dev/null
+++ b/sprint5-prep-exercises/methods.py
@@ -0,0 +1,23 @@
+import datetime as dt
+from dataclasses import dataclass
+
+
+@dataclass
+class Person:
+    name: str
+    birthdate: dt.date
+    preferred_operating_system: str
+
+    def is_adult(self) -> bool:
+        today = dt.date.today()
+        age = today.year - self.birthdate.year
+
+        if (today.month, today.day) < (self.birthdate.month, self.birthdate.day):
+            age -= 1
+
+        return age >= 18
+
+
+imran = Person("Imran", dt.date(2000, 8, 6), "Ubuntu")
+
+print(imran.is_adult())
\ No newline at end of file
diff --git a/sprint5-prep-exercises/typeAnnotations.py b/sprint5-prep-exercises/typeAnnotations.py
index 5aeb69840..cdb4f1742 100644
--- a/sprint5-prep-exercises/typeAnnotations.py
+++ b/sprint5-prep-exercises/typeAnnotations.py
@@ -32,4 +32,8 @@ def format_pence_as_string(total_pence: int) -> str:
 total_pence = sum_balances(balances)
 total_string = format_pence_as_string(total_pence)
 
-print(f"The bank accounts total {total_string}")
\ No newline at end of file
+print(f"The bank accounts total {total_string}")
+def is_adult(person: Person) -> bool:
+    return person.age >= 18
+
+print(is_adult(imran))
\ No newline at end of file

From 45b9d4c06bd44643a3e7a5d0a809f411845e7c06 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Tue, 11 Aug 2026 14:38:20 +0100
Subject: [PATCH 06/13]  changing the type annotation of
 Person.preferred_operating_system from str to List[str]

---
 sprint5-prep-exercises/prefOperatingSys.py | 42 ++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 sprint5-prep-exercises/prefOperatingSys.py

diff --git a/sprint5-prep-exercises/prefOperatingSys.py b/sprint5-prep-exercises/prefOperatingSys.py
new file mode 100644
index 000000000..a63acde5a
--- /dev/null
+++ b/sprint5-prep-exercises/prefOperatingSys.py
@@ -0,0 +1,42 @@
+from dataclasses import dataclass
+from typing import List
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    preferred_operating_systems: list[str]
+
+
+@dataclass(frozen=True)
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    screen_size_in_inches: float
+    operating_system: str
+
+
+def find_possible_laptops(laptops: List[Laptop], person: Person) -> List[Laptop]:
+    possible_laptops = []
+    for laptop in laptops:
+        if laptop.operating_system == person.preferred_operating_systems:
+            possible_laptops.append(laptop)
+    return possible_laptops
+
+
+people = [
+    Person(name="Imran", age=22, preferred_operating_systems=["Ubuntu"]),
+    Person(name="Eliza", age=34, preferred_operating_systems=["Arch Linux"]),
+]
+
+laptops = [
+    Laptop(id=1, manufacturer="Dell", model="XPS", screen_size_in_inches=13, operating_system="Arch Linux"),
+    Laptop(id=2, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system="Ubuntu"),
+    Laptop(id=3, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system="ubuntu"),
+    Laptop(id=4, manufacturer="Apple", model="macBook", screen_size_in_inches=13, operating_system="macOS"),
+]
+
+for person in people:
+    possible_laptops = find_possible_laptops(laptops, person)
+    print(f"Possible laptops for {person.name}: {possible_laptops}")
\ No newline at end of file

From 6991373bbdf9f33953e5dd59f866f6a5df1042df Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Tue, 11 Aug 2026 22:37:58 +0100
Subject: [PATCH 07/13] implementing a program about  a library has to lend out

---
 sprint5-prep-exercises/enums.py | 96 +++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 sprint5-prep-exercises/enums.py

diff --git a/sprint5-prep-exercises/enums.py b/sprint5-prep-exercises/enums.py
new file mode 100644
index 000000000..a133d0799
--- /dev/null
+++ b/sprint5-prep-exercises/enums.py
@@ -0,0 +1,96 @@
+from dataclasses import dataclass
+from enum import Enum
+import sys
+
+
+class OperatingSystem(Enum):
+    MACOS = "macOS"
+    ARCH = "Arch Linux"
+    UBUNTU = "Ubuntu"
+
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    preferred_operating_system: OperatingSystem
+
+
+@dataclass(frozen=True)
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    screen_size_in_inches: float
+    operating_system: OperatingSystem
+
+
+laptops = [
+    Laptop(1, "Dell", "XPS", 13, OperatingSystem.ARCH),
+    Laptop(2, "Dell", "XPS", 15, OperatingSystem.UBUNTU),
+    Laptop(3, "Dell", "XPS", 15, OperatingSystem.UBUNTU),
+    Laptop(4, "Apple", "MacBook", 13, OperatingSystem.MACOS),
+]
+
+
+# Get the person's name
+name = input("What is your name? ")
+
+
+# Get and convert age
+try:
+    age = int(input("What is your age? "))
+except ValueError:
+    print("Age must be a number.", file=sys.stderr)
+    sys.exit(1)
+
+
+# Get and convert operating system
+try:
+    os_input = input("What is your preferred operating system? ")
+    operating_system = OperatingSystem(os_input)
+except ValueError:
+    print("Invalid operating system.", file=sys.stderr)
+    sys.exit(1)
+
+
+person = Person(
+    name=name,
+    age=age,
+    preferred_operating_system=operating_system,
+)
+
+
+# Count laptops with the person's preferred OS
+number_available = sum(
+    laptop.operating_system == person.preferred_operating_system
+    for laptop in laptops
+)
+
+
+print(
+    f"We have {number_available} laptop(s) with "
+    f"{person.preferred_operating_system.value}."
+)
+
+
+# Find the operating system with the most laptops
+counts = {}
+
+for os in OperatingSystem:
+    counts[os] = sum(
+        laptop.operating_system == os
+        for laptop in laptops
+    )
+
+
+most_available_os = max(counts, key=counts.get)
+
+
+if most_available_os != person.preferred_operating_system:
+    if counts[most_available_os] > number_available:
+        print(
+            f"If you are willing to use {most_available_os.value}, "
+            f"you are more likely to get a laptop because we have "
+            f"{counts[most_available_os]} available."
+        )
\ No newline at end of file

From f4dfc058e2380ab415177b5a43fdab69efd03ba5 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Wed, 12 Aug 2026 10:26:10 +0100
Subject: [PATCH 08/13] comments that explain what each line does in
 predictInheritance.py

---
 sprint5-prep-exercises/PredictInheritance.py | 58 ++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 sprint5-prep-exercises/PredictInheritance.py

diff --git a/sprint5-prep-exercises/PredictInheritance.py b/sprint5-prep-exercises/PredictInheritance.py
new file mode 100644
index 000000000..beb48aaad
--- /dev/null
+++ b/sprint5-prep-exercises/PredictInheritance.py
@@ -0,0 +1,58 @@
+# Parent class stores a person's first name and last name
+class Parent:
+    def __init__(self, first_name: str, last_name: str):
+        self.first_name = first_name
+        self.last_name = last_name
+    # Returns the person's first and last name together
+    def get_name(self) -> str:
+        return f"{self.first_name} {self.last_name}"
+
+# Child inherits the fields and methods from Parent
+# It also allows the person to change their last name
+class Child(Parent):
+    def __init__(self, first_name: str, last_name: str):
+        super().__init__(first_name, last_name)
+        self.previous_last_names = []
+    # Changes the last name and saves the old name
+    def change_last_name(self, last_name) -> None:
+        self.previous_last_names.append(self.last_name)
+        self.last_name = last_name
+   # Returns the current name and the original last name
+    def get_full_name(self) -> str:
+        suffix = ""
+        if len(self.previous_last_names) > 0:
+            suffix = f" (née {self.previous_last_names[0]})"
+        return f"{self.first_name} {self.last_name}{suffix}"
+# Create child object
+person1 = Child("Elizaveta", "Alekseeva")
+# Child inherits get_name() from Parent
+# Output: Elizaveta Alekseeva
+print(person1.get_name())
+# Child has its own get_full_name() method
+# Output: Elizaveta Alekseeva
+print(person1.get_full_name())
+# Change the last name 
+person1.change_last_name("Tyurina")
+# The current last name is now Tyurina
+# Output: Elizaveta Tyurina
+print(person1.get_name())
+# Shows the new name and the previous last name
+# Output: Elizaveta Tyurina (née Alekseeva)
+print(person1.get_full_name())
+# Create a Parent object
+person2 = Parent("Elizaveta", "Alekseeva")
+# Parent has get_name(), so this works
+# Output: Elizaveta Alekseeva
+print(person2.get_name())
+# This causes an AttributeError because Parent
+# does not have a get_full_name() method
+print(person2.get_full_name())
+# This also causes an AttributeError because Parent
+# does not have a change_last_name() method
+person2.change_last_name("Tyurina")
+# get_name() still works because it belongs to Parent
+# Output: Elizaveta Alekseeva
+print(person2.get_name())
+# This would cause another AttributeError
+# because get_full_name() only exists in Child
+print(person2.get_full_name())
\ No newline at end of file

From 9f25002aab33392a6520d85a0bbe25ddeb352b22 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Wed, 12 Aug 2026 11:51:15 +0100
Subject: [PATCH 09/13] refactoring the code

---
 sprint5-prep-exercises/prefOperatingSys.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/sprint5-prep-exercises/prefOperatingSys.py b/sprint5-prep-exercises/prefOperatingSys.py
index a63acde5a..0532fd461 100644
--- a/sprint5-prep-exercises/prefOperatingSys.py
+++ b/sprint5-prep-exercises/prefOperatingSys.py
@@ -39,4 +39,10 @@ def find_possible_laptops(laptops: List[Laptop], person: Person) -> List[Laptop]
 
 for person in people:
     possible_laptops = find_possible_laptops(laptops, person)
-    print(f"Possible laptops for {person.name}: {possible_laptops}")
\ No newline at end of file
+    print(f"Possible laptops for {person.name}: {possible_laptops}")
+
+
+
+    # Yes, at first, when I changed str to list[str],
+    #  mypy showed errors as I expected because I was still passing strings instead of lists
+    # Then I changed the field name to the plural form `preferred_operating_systems` to match the fact that it is now a list.

From af4fe85a6f8c792444ce85b96879606699919e99 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Fri, 14 Aug 2026 08:20:42 +0100
Subject: [PATCH 10/13] adding  methodsAndFunctions.tx file

---
 sprint5-prep-exercises/methodsAndFunctions.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 sprint5-prep-exercises/methodsAndFunctions.txt

diff --git a/sprint5-prep-exercises/methodsAndFunctions.txt b/sprint5-prep-exercises/methodsAndFunctions.txt
new file mode 100644
index 000000000..4f7036323
--- /dev/null
+++ b/sprint5-prep-exercises/methodsAndFunctions.txt
@@ -0,0 +1,17 @@
+Advantages of Using Methods Instead of Free Functions
+# Easier to maintain
+   Methods keep related operations inside the class, making the program more organized and easier to update.
+# Better data protection
+   A method can control how the object's data is changed and prevent invalid changes.
+# Simple to use
+    Methods can be called using dot notation, such as account.deposit(100), which makes the code easy to read.
+# Hides unnecessary details
+    Users only need to know what a method does and how to call it. They don't need to understand all the code inside it.
+# Keeps data and behaviour together
+    A class can contain both the information about an object and the methods that work with that information.
+# Can be reused with different objects
+    Once a method is defined in a class, objects created from that class can use the same method.
+# Allows rules to be enforced
+    Methods can make sure that data is changed in a safe and valid way. For example, a withdraw() method could prevent a bank account from having a negative balance.
+In short: methods are useful because they make code more organized,
+reusable, easier to understand, and safer to manage, especially when working with objects and their data.

From 172f9c60af5e92522f0c4183b766fec59fdae1f0 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Fri, 14 Aug 2026 08:46:00 +0100
Subject: [PATCH 11/13] adding the missing code in typeAnnotation.py file

---
 sprint5-prep-exercises/generics.py        | 20 ++++++++++++++++++++
 sprint5-prep-exercises/typeAnnotations.py | 17 ++++-------------
 2 files changed, 24 insertions(+), 13 deletions(-)
 create mode 100644 sprint5-prep-exercises/generics.py

diff --git a/sprint5-prep-exercises/generics.py b/sprint5-prep-exercises/generics.py
new file mode 100644
index 000000000..0f857f27a
--- /dev/null
+++ b/sprint5-prep-exercises/generics.py
@@ -0,0 +1,20 @@
+from dataclasses import dataclass
+from typing import List
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    children: List["Person"]
+    age: int
+
+fatma = Person(name="Fatma", children=[], age=10)
+aisha = Person(name="Aisha", children=[], age=13)
+
+imran = Person(name="Imran", children=[fatma, aisha], age=50)
+
+def print_family_tree(person: Person) -> None:
+    print(person.name)
+    for child in person.children:
+        print(f"- {child.name} ({child.age})")
+
+print_family_tree(imran)
\ No newline at end of file
diff --git a/sprint5-prep-exercises/typeAnnotations.py b/sprint5-prep-exercises/typeAnnotations.py
index cdb4f1742..42ddc6920 100644
--- a/sprint5-prep-exercises/typeAnnotations.py
+++ b/sprint5-prep-exercises/typeAnnotations.py
@@ -1,16 +1,13 @@
-
-def open_account(balances: dict[str, int], name: str, amount: int):
+from typing import Dict
+def open_account(balances: dict, name: str, amount: int)-> None:
     balances[name] = amount
-
-
-def sum_balances(accounts: dict[str, int]) -> int:
+def sum_balances(accounts: Dict[str, int]) -> int:
     total = 0
     for name, pence in accounts.items():
         print(f"{name} had balance {pence}")
         total += pence
     return total
 
-
 def format_pence_as_string(total_pence: int) -> str:
     if total_pence < 100:
         return f"{total_pence}p"
@@ -18,14 +15,12 @@ def format_pence_as_string(total_pence: int) -> str:
     pence = total_pence % 100
     return f"£{pounds}.{pence:02d}"
 
-
-balances: dict[str, int] = {
+balances = {
     "Sima": 700,
     "Linn": 545,
     "Georg": 831,
 }
 
-
 open_account(balances, "Tobi", 913)
 open_account(balances, "Olya", 713)
 
@@ -33,7 +28,3 @@ def format_pence_as_string(total_pence: int) -> str:
 total_string = format_pence_as_string(total_pence)
 
 print(f"The bank accounts total {total_string}")
-def is_adult(person: Person) -> bool:
-    return person.age >= 18
-
-print(is_adult(imran))
\ No newline at end of file

From e9ba778824cea30078ae62ee0b4717f10e98f228 Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Fri, 14 Aug 2026 08:53:57 +0100
Subject: [PATCH 12/13]  refactoring prefOpratingSys.py file

---
 sprint5-prep-exercises/prefOperatingSys.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/sprint5-prep-exercises/prefOperatingSys.py b/sprint5-prep-exercises/prefOperatingSys.py
index 0532fd461..c957aae9c 100644
--- a/sprint5-prep-exercises/prefOperatingSys.py
+++ b/sprint5-prep-exercises/prefOperatingSys.py
@@ -20,7 +20,7 @@ class Laptop:
 def find_possible_laptops(laptops: List[Laptop], person: Person) -> List[Laptop]:
     possible_laptops = []
     for laptop in laptops:
-        if laptop.operating_system == person.preferred_operating_systems:
+       if laptop.operating_system in person.preferred_operating_systems:
             possible_laptops.append(laptop)
     return possible_laptops
 
@@ -41,8 +41,6 @@ def find_possible_laptops(laptops: List[Laptop], person: Person) -> List[Laptop]
     possible_laptops = find_possible_laptops(laptops, person)
     print(f"Possible laptops for {person.name}: {possible_laptops}")
 
-
-
     # Yes, at first, when I changed str to list[str],
     #  mypy showed errors as I expected because I was still passing strings instead of lists
     # Then I changed the field name to the plural form `preferred_operating_systems` to match the fact that it is now a list.

From 1b2d91c7019221419771ca0f0cfab85466f9a6db Mon Sep 17 00:00:00 2001
From: shreefAhmedM <livecoding.33@gmail.com>
Date: Fri, 14 Aug 2026 09:09:16 +0100
Subject: [PATCH 13/13] inhancing the UI and validation in enums.py file

---
 sprint5-prep-exercises/enums.py | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/sprint5-prep-exercises/enums.py b/sprint5-prep-exercises/enums.py
index a133d0799..6d3c532fa 100644
--- a/sprint5-prep-exercises/enums.py
+++ b/sprint5-prep-exercises/enums.py
@@ -33,11 +33,8 @@ class Laptop:
 ]
 
 
-# Get the person's name
 name = input("What is your name? ")
 
-
-# Get and convert age
 try:
     age = int(input("What is your age? "))
 except ValueError:
@@ -45,11 +42,19 @@ class Laptop:
     sys.exit(1)
 
 
-# Get and convert operating system
+print("Available operating systems:")
+for os in OperatingSystem:
+    print(os.value)
+
 try:
-    os_input = input("What is your preferred operating system? ")
-    operating_system = OperatingSystem(os_input)
-except ValueError:
+    os_input = input("What is your preferred operating system? ").strip().lower()
+
+    operating_system = next(
+        os for os in OperatingSystem
+        if os.value.lower() == os_input
+    )
+
+except StopIteration:
     print("Invalid operating system.", file=sys.stderr)
     sys.exit(1)
 
@@ -61,21 +66,18 @@ class Laptop:
 )
 
 
-# Count laptops with the person's preferred OS
 number_available = sum(
     laptop.operating_system == person.preferred_operating_system
     for laptop in laptops
 )
 
-
 print(
     f"We have {number_available} laptop(s) with "
     f"{person.preferred_operating_system.value}."
 )
 
 
-# Find the operating system with the most laptops
-counts = {}
+counts: dict[OperatingSystem, int] = {}
 
 for os in OperatingSystem:
     counts[os] = sum(
@@ -86,7 +88,6 @@ class Laptop:
 
 most_available_os = max(counts, key=counts.get)
 
-
 if most_available_os != person.preferred_operating_system:
     if counts[most_available_os] > number_available:
         print(