Add laptop library with enum validation and OS availability check

Author: SaraTahir28

Sprint5/e-num.py

@@ -0,0 +1,90 @@
+from dataclasses import dataclass
+from enum import Enum
+from typing import List
+import sys
+
+
+class OperatingSystem(Enum):
+    MACOS = "macOS"
+    ARCH = "Arch Linux"
+    UBUNTU = "Ubuntu"
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    preferred_os: OperatingSystem
+
+
+@dataclass(frozen=True)
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    screen_size_in_inches: float
+    operating_system: OperatingSystem
+
+#library of laptops
+laptops = [
+    Laptop(id=1, manufacturer="Dell", model="XPS", screen_size_in_inches=13, operating_system=OperatingSystem.ARCH),
+    Laptop(id=2, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system=OperatingSystem.UBUNTU),
+    Laptop(id=3, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system=OperatingSystem.UBUNTU),
+    Laptop(id=4, manufacturer="Apple", model="macBook", screen_size_in_inches=13, operating_system=OperatingSystem.MACOS),
+]
+
+def find_possible_laptops(laptops: List[Laptop], person: Person) -> List[Laptop]:
+    possible_laptops = []
+    for laptop in laptops:
+        if laptop.operating_system == person.preferred_os:
+            possible_laptops.append(laptop)
+    return possible_laptops   # returns an array of possible laptops for the person
+
+ #accept userinput 
+name = input("Enter your name: ").strip()
+age_str = input("Enter your age: ").strip()  #input always returns a str, we need to convert this to an integer
+os_str = input("Enter your preferred operating system: ").strip()
+# Validate age
+try:
+    age = int(age_str)
+except ValueError:
+    print("Error: Age must be a number.", file= sys.stderr)
+    sys.exit(1)
+
+# Validate OS
+try:
+    preferred_os = OperatingSystem(os_str)
+except ValueError:
+    print("Error: Invalid operating system.", file=sys.stderr)
+    sys.exit(1)
+
+#Create a person after validation 
+person = Person(name = name, age = age, preferred_os =preferred_os)
+#finding laptops for this person 
+possible = find_possible_laptops(laptops, person)
+print(f"The laptop library  has {len(possible)} with {preferred_os.value}.")
+
+# Start with an empty dictionary
+os_counts: dict[OperatingSystem, int] = {}
+
+for laptop in laptops:
+    os = laptop.operating_system
+    # If we've seen this OS before, add 1, otherwise start at 1
+    if os in os_counts:
+        os_counts[os] += 1
+    else:
+        os_counts[os] = 1
+
+best_os = None
+best_count = -1
+
+# Loop through each (key, value) pair
+for pair in os_counts.items():
+    os = pair[0]    # the key (operating system)
+    count = pair[1] # the value (number of laptops)
+
+    # Check if this count is bigger than the best so far
+    if count > best_count:
+        best_os = os
+        best_count = count
+
+print("Best OS:", best_os, "with", best_count, "laptops")