Complete exercises for Module Tools/Sprint 5/Prep - step 8 'enums'

Author: Geraldine-Edwards

prep-exercises/h_enums.py

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+import sys
+from dataclasses import dataclass
+from enum import Enum
+from typing import List
+from collections import Counter
+
+class OperatingSystem(Enum):
+    MACOS = "macOS"
+    ARCH = "Arch Linux"
+    UBUNTU = "Ubuntu"
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    preferred_operating_systems: OperatingSystem
+
+
+@dataclass(frozen=True)
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    screen_size_in_inches: float
+    operating_system: OperatingSystem
+
+def find_possible_laptops(available_laptops: List[Laptop], current_person: Person) -> List[Laptop]:
+    return [
+        laptop for laptop in available_laptops
+        if laptop.operating_system == current_person.preferred_operating_systems
+    ]
+
+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),
+    Laptop(id=5, manufacturer="Apple", model="MacBook Air", screen_size_in_inches=13, operating_system=OperatingSystem.MACOS),
+    Laptop(id=6, manufacturer="Lenovo", model="ThinkPad", screen_size_in_inches=14, operating_system=OperatingSystem.ARCH),
+    Laptop(id=7, manufacturer="Asus", model="ZenBook", screen_size_in_inches=13, operating_system=OperatingSystem.UBUNTU),
+    Laptop(id=8, manufacturer="HP", model="Spectre", screen_size_in_inches=14, operating_system=OperatingSystem.MACOS),
+    Laptop(id=9, manufacturer="Apple", model="MacBook Pro", screen_size_in_inches=16, operating_system=OperatingSystem.MACOS),
+]
+
+# ------------------------
+# Exercise 1
+# ------------------------
+#  Write a program which:
+#  - Already has a list of Laptops that a library has to lend out.
+#  - Accepts user input to create a new Person - it should use the input function to read a person’s name, age, 
+#    and preferred operating system.
+#  - Tells the user how many laptops the library has that have that operating system.
+#  - If there is an operating system that has more laptops available, tells the user that if they’re willing 
+#    to accept that operating system they’re more likely to get a laptop.
+#  You should convert the age and preferred operating system input from the user into more constrained types as quickly 
+#  as possible, and should output errors to stderr and terminate the program with a non-zero exit code if the
+#  user input bad values.
+
+def user_prompt() -> Person:
+    try:
+        name = str(input("Please enter your first name: "))
+        if not name.isalpha():
+            raise ValueError("Name must contain only alphabetic characters.")
+        
+        age = int(input("Please enter your age: "))
+        if age <= 0:
+            raise ValueError("Age must be positive.")
+        
+        # define valid OS options
+        valid_os = [os.value for os in OperatingSystem]
+
+        # dynamically display the os options
+        preferred_os = input(f"Please enter correct operating system name, either {', '.join(valid_os)}: ").strip()
+
+        # validate the OS
+        if preferred_os not in valid_os:
+            raise ValueError("Invalid operating system.")
+    
+        # convert to enum
+        preferred_os_enum = OperatingSystem(preferred_os)
+
+        return Person(name=name, age=age, preferred_operating_systems=preferred_os_enum)
+ 
+    # throw an error and exit for invalid age and os input
+    except ValueError as error:
+        print(f"Invalid input: {error}", file=sys.stderr)
+        sys.exit(1)
+
+
+
+def main() -> None:
+
+    user_details = user_prompt()
+
+    matching_laptops = find_possible_laptops(laptops, user_details)
+
+    # get the counts of the laptops for an OS e.g. os_counts = {OperatingSystem.MACOS: 4,OperatingSystem.ARCH: 2,OperatingSystem.UBUNTU: 3}
+    os_counts = Counter(laptop.operating_system for laptop in laptops)
+
+    print(f"{user_details.name}, there are {len(matching_laptops)} laptops available with your preferred operating system ({user_details.preferred_operating_systems.value}).")
+
+    if matching_laptops:
+        print("Matching laptops:")
+        for laptop in matching_laptops:
+            print(f"- {laptop.manufacturer} {laptop.model} ({laptop.screen_size_in_inches}\" screen)")
+    else:
+        print("No laptops available with your preferred operating system.")
+
+    # get the count of laptops for users preferred OS
+    user_os_count = os_counts[user_details.preferred_operating_systems]
+
+    # find the OSes with more laptops available
+    alternative_os = [(os, count) for os, count in os_counts.items() if count > user_os_count]
+
+    if alternative_os:
+        print("However, there are more laptops available with the following operating systems:")
+        for os, count in alternative_os:
+            print(f"- {os.value}: {count} laptops")
+        print("If you consider one of these options, you will have a greater chance of getting a laptop.")
+    else: 
+        print("Your preferred operating system has the most laptops available.")
+
+if __name__ == "__main__":
+    main()