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Принципы разработки программного обеспечения на Python

Adam Spannbauer

Machine Learning Engineer

Дзен Python

import this

The Zen of Python, by Tim Peters (abridged)

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
The complex is better than complicated.
Readability counts.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.

Описательные имена

Неудачные имена

def check(x, y=100):
    return x >= y

Описательные имена

def is_boiling(temp, boiling_point=100):
    return temp >= boiling_point

Перегиб

def check_if_temperature_is_above_boiling_point(
        temperature_to_check, 
        celsius_water_boiling_point=100):
    return temperature_to_check >= celsius_water_boiling_point

Простота — залог качества

The Zen of Python, by Tim Peters (abridged)

Simple is better than complex.
Complex is better than complicated.

Кусок пиццы

Приготовление пиццы — сложный вариант

def make_pizza(ingredients):
    # Make dough
    dough = mix(ingredients['yeast'],
                ingredients['flour'],
                ingredients['water'],
                ingredients['salt'],
                ingredients['shortening'])

    kneaded_dough = knead(dough)
    risen_dough = prove(kneaded_dough)

    # Make sauce
    sauce_base = sautee(ingredients['onion'],
                                ingredients['garlic'],
                                ingredients['olive oil'])

    sauce_mixture = combine(sauce_base,
                            ingredients['tomato_paste'],
                            ingredients['water'],
                            ingredients['spices'])

    sauce = simmer(sauce_mixture)
    ...

Приготовление пиццы — простой вариант

def make_pizza(ingredients):
    dough = make_dough(ingredients)
    sauce = make_sauce(ingredients)
    assembled_pizza = assemble_pizza(dough, sauce, ingredients)

    return bake(assembled_pizza)

Когда стоит рефакторить

Неудачные имена

def check(x, y=100):
    return x >= y

Описательные имена

def is_boiling(temp, boiling_point=100):
    return temp >= boiling_point

Перегиб

def check_if_temperature_is_above_boiling_point(
        temperature_to_check, 
        celsius_water_boiling_point=100):
    return temperature_to_check >= celsius_water_boiling_point

Давайте потренируемся!

Принципы разработки программного обеспечения на Python