def human_name(self):
    raise NotImplementedError

from abc import ABCMeta, abstractmethod

class Service(metaclass=ABCMeta):
    @abstractmethod
    def human_name(self):
        pass

import typer

app = typer.Typer()

@app.command()
def hello(name: str, age: int = 18):
    print(f"Привет, {name}! Тебе {age} лет.")

if __name__ == "__main__":
    app()

$ python main.py hello Alice --age 30
Привет, Alice! Тебе 30 лет.

class Foo:
    def __new__(cls, x):
        return dict(x=x)

    def __init__(self, x):
        print(x)  # Никогда не вызывается

print(Foo(0))

class Foo:
    def __new__(cls, x):
        return Foo(-x)  # Рекурсия

class Foo:
    def __new__(cls, x):
        if x < 0:
            return Foo(-x)
        return super().__new__(cls)

    def __init__(self, x):
        print(x)
        self._x = x

class Foo:
    def __new__(cls, x):
        if x < 0:
            return cls.__new__(cls, -x)
        return super().__new__(cls)

    def __init__(self, x):
        print(x)
        self._x = x

>>> format(0.1, '.17f')
'0.10000000000000001'

>>> from decimal import Decimal
>>> Decimal(1) / Decimal(3)
Decimal('0.3333333333333333333333333333')

>>> Decimal(1) / Decimal(3) * Decimal(3) == Decimal(1)
False

>>> from fractions import Fraction
>>> Fraction(1) / Fraction(3) * Fraction(3) == Fraction(1)
True

from functools import partial

send_html_email = partial(send_email, is_html=True)

# Теперь можно вызывать проще:
send_html_email("user@example.com", "Привет", "<b>Как дела?</b>")

import logging

def setup_logger(name: str) -> logging.Logger:
    logger = logging.getLogger(name)
    if not logger.hasHandlers():
        logger.setLevel(logging.INFO)
        handler = logging.StreamHandler()
        formatter = logging.Formatter(
            '%(asctime)s - %(levelname)s - %(name)s - %(message)s'
        )
        handler.setFormatter(formatter)
        logger.addHandler(handler)
    return logger

logger = setup_logger(__name__)

logger.info("Скрипт стартовал")