enum exer.

Author: Nataliia74

enums.py

@@ -0,0 +1,105 @@
+from dataclasses import dataclass
+from enum import Enum
+from typing import List, Dict
+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
+
+
+def count_laptops(laptops: List[Laptop]) -> Dict[OperatingSystem, int]:
+    number_eachOS_laptops: Dict[OperatingSystem, int] = {
+        OperatingSystem.MACOS: 0,
+        OperatingSystem.ARCH: 0,
+        OperatingSystem.UBUNTU: 0}
+    for laptop in laptops:
+        number_eachOS_laptops[laptop.operating_system] +=1
+    return number_eachOS_laptops
+
+
+def count_possible_laptops(laptops: List[Laptop], person: Person) -> int:
+    possible_laptops: List[Laptop] =[]
+    for laptop in laptops:
+        if laptop.operating_system == person.preferred_operating_system:
+            possible_laptops.append(laptop)
+    number_possible_laptops = len(possible_laptops)
+    return number_possible_laptops
+
+def chose_alternative_laptops(laptops: List[Laptop], person: Person) -> Dict[OperatingSystem, int]:
+    number_possible_laptops = count_possible_laptops(laptops, person)
+    number_eachOS_laptops = count_laptops(laptops)
+    preferred_os = person.preferred_operating_system
+    alternative_laptops: Dict[OperatingSystem, int] = {}
+    for eachOS, count in number_eachOS_laptops.items():
+        if eachOS == preferred_os:
+            continue
+        if count > number_possible_laptops:
+            alternative_laptops[eachOS] = count
+    if len(alternative_laptops) != 0:
+        print(f"There is an operating system that has more laptops available.If you’re willing to accept them, there is a list: {alternative_laptops}.")
+        return alternative_laptops
+    else:
+        print("There is not an operating system that has more laptops available.")
+        return alternative_laptops
+
+while True:
+    user_name = input("Type your name: ").strip()
+    if len(user_name) < 3:
+        print(f"Error, {user_name} is not valid. Try again, length should be more than 3 characters.")
+        continue
+    break
+
+while True:
+    user_age = input("Type your age: ").strip()
+    try:
+        user_age_int = int(user_age)
+        if user_age_int < 18:
+            raise ValueError
+        break
+    except ValueError:
+        print("Invalid age, try again! Borrowing allowed from 18 years old.")
+
+available_os = [os.value for os in OperatingSystem]
+print("Available OSs are: ", ",".join(available_os))
+user_operating_system = input("Type operating system: ").strip()
+if user_operating_system not in available_os:
+    print(f"Error, {user_operating_system} is not in available list\n"
+    f"Available OSs are: {','.join(available_os)}", file=sys.stderr)
+    sys.exit(1)
+
+preferred_operating_system = OperatingSystem(user_operating_system)
+
+user = Person(name=user_name, age=user_age_int, preferred_operating_system=preferred_operating_system)
+
+
+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),
+]
+
+
+possible_laptops = count_possible_laptops(laptops, user)
+print(f"Possible laptops for {user_name}: {possible_laptops}")
+alternative_laptops = chose_alternative_laptops(laptops, user)