London | 25-SDC-July | Andrei Filippov | Sprint 4 | Prep Exercises

.gitignore

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+.venv
+node_modules
+.ds_store

bank_accounts.py

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+def open_account(balances: dict[str, int], name: str, amount: int) -> None:
+    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 = {
+    "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}")

classes_and_objects.py

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+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) address is not an attribute of the Person class
+
+eliza = Person("Eliza", 34, "Arch Linux")
+print(eliza.name)
+# print(eliza.address)
+
+
+def is_adult(person: Person) -> bool:
+    return person.age >= 18
+
+
+print(is_adult(imran))
+
+
+# Exercise:
+# Write a new function in the file that accepts a Person as a parameter and tries to access a property that
+#  doesn’t exist. Run it through mypy and check that it does report an error.
+
+
+def live_in_london(person: Person) -> bool:
+    return person.address == "London"
+
+
+live_in_london(imran)

dataclass.py

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+from datetime import date
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    date_of_birth: date
+    preferred_operating_system: str
+
+    def is_adult(self) -> bool:
+        eighteen_birthday = date(
+            self.date_of_birth.year + 18,
+            self.date_of_birth.month,
+            self.date_of_birth.day,
+        )
+        return date.today() >= eighteen_birthday
+
+
+imran = Person("Imran", date(2019, 12, 22), "Ubuntu")
+print(imran.is_adult())
+
+imran2 = Person("Imran2", date(2000, 12, 22), "Ubuntu")
+print(imran2.is_adult())
+
+print(imran == imran2)

double.py

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+def half(value):
+    return value / 2
+
+
+def double(value):
+    return value * 2
+
+
+def second(value):
+    return value[1]
+
+
+# ✍️exercise
+# Predict what double("22") will do. Then run the code and check. Did it do what you expected? Why did it return the value it did
+
+# Answer
+# double "22" will return "2222" because when we multiply string, code write that string several times

enums.py

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+from dataclasses import dataclass
+from enum import Enum
+import sys
+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_system: OperatingSystem
+
+
+@dataclass(frozen=True)
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    screen_size_in_inches: float
+    operating_system: OperatingSystem
+
+
+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,
+    ),
+]
+
+
+users = []
+
+
+def find_possible_laptops(laptops: list[Laptop], person: Person) -> list[Laptop]:
+    possible_laptops = []
+    for laptop in laptops:
+        if laptop.operating_system == person.preferred_operating_system:
+            possible_laptops.append(laptop)
+    return possible_laptops
+
+
+def input_validation() -> tuple[str, int, OperatingSystem]:
+    input_user_name = input("Enter your name: ")
+    if not isinstance(input_user_name, str):
+        sys.stderr.write("Name must be a string")
+        sys.exit(1)
+
+    try:
+        input_user_age = int(input("Enter your age: "))
+    except ValueError:
+        sys.stderr.write("Age must be an integer")
+        sys.exit(1)
+
+    input_preferred_operating_system = input(
+        "Enter your preferred operating system (macOS/Arch Linux/Ubuntu): "
+    )
+
+    try:
+        preferred_os = OperatingSystem(input_preferred_operating_system)
+    except ValueError:
+        sys.stderr.write("Wrong OS")
+        sys.exit(1)
+
+    return input_user_name, input_user_age, preferred_os
+
+
+def count_operating_systems(laptops: list[Laptop]) -> Counter[OperatingSystem]:
+    return Counter(laptop.operating_system for laptop in laptops)
+
+
+def recommend_os(user: Person, laptops: list[Laptop]) -> None:
+    os_counts = count_operating_systems(laptops)
+    most_common_os, most_common_count = os_counts.most_common(1)[0]
+
+    user_preferred_os = os_counts[user.preferred_operating_system]
+
+    if (
+        most_common_os != user.preferred_operating_system
+        and user_preferred_os < most_common_count
+    ):
+        print(f"More laptops are available with {most_common_os.value}.")
+
+
+def laptop() -> None:
+    input_user_name, input_user_age, input_preferred_operating_system = (
+        input_validation()
+    )
+
+    users.append(
+        Person(
+            name=input_user_name,
+            age=input_user_age,
+            preferred_operating_system=OperatingSystem(
+                input_preferred_operating_system
+            ),
+        ),
+    )
+    for user in users:
+        possible_laptops = find_possible_laptops(laptops, user)
+        print(
+            f"Possible laptops for {user.name}:\n{'\n'.join(map(str, possible_laptops))}",
+        )
+        recommend_os(user, laptops)
+
+
+laptop()

generics.py

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+from dataclasses import dataclass
+from typing import List
+
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    children: List["Person"]
+
+
+fatma = Person(name="Fatma", age=5, children=[])
+aisha = Person(name="Aisha", age=20, children=[])
+
+imran = Person(name="Imran", age=49, children=[fatma, aisha])
+
+
+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)

inheritance.py

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+class Parent:
+    def __init__(self, first_name: str, last_name: str):
+        self.first_name = first_name
+        self.last_name = last_name
+
+    def get_name(self) -> str:
+        return f"{self.first_name} {self.last_name}"
+
+
+class Child(Parent):
+    def __init__(self, first_name: str, last_name: str):
+        super().__init__(first_name, last_name)
+        self.previous_last_names = []
+
+    def change_last_name(self, last_name) -> None:
+        self.previous_last_names.append(self.last_name)
+        self.last_name = 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}"
+
+
+person1 = Child("Elizaveta", "Alekseeva")
+print(person1.get_name())
+print(person1.get_full_name())
+person1.change_last_name("Tyurina")
+print(person1.get_name())
+print(person1.get_full_name())
+
+person2 = Parent("Elizaveta", "Alekseeva")
+print(person2.get_name())
+# print(person2.get_full_name())
+# person2.change_last_name("Tyurina")
+print(person2.get_name())
+# print(person2.get_full_name())
+# Commented out these prints because the Parent class doesn't have these methods, which causes an "AttributeError"

is_adult.py

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+from datetime import date
+
+
+class Person:
+    def __init__(self, name: str, date_of_birth: date, preferred_operating_system: str):
+        self.name = name
+        self.date_of_birth = date_of_birth
+        self.preferred_operating_system = preferred_operating_system
+
+    def is_adult(self) -> bool:
+        eighteen_birthday = date(
+            self.date_of_birth.year + 18,
+            self.date_of_birth.month,
+            self.date_of_birth.day,
+        )
+        return date.today() >= eighteen_birthday
+
+
+imran = Person("Imran", date(2019, 12, 22), "Ubuntu")
+print(imran.is_adult())

requirements.txt

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+mypy