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Python Code Samples

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2 matches
System design patterns easy

How to Implement the Repository Pattern in Python with an In-Memory Dict

Stores, retrieves, updates, and deletes user records in memory using a Repository abstraction over a plain dict, isolating data access from business logic.

repository-pattern design-patterns in-memory
Python
class UserRepository:
    def __init__(self):
        self._storage = {}
        self._next_id = 1

    def create(self, name, email):
        user_id = self._next_id
        self._next_id += 1
        self._storage[user_id] = {"id": user_id, "name": name, "email": email}
        return self._storage[user_id]

    def…
11 0 Open
System design patterns easy

How to mock the domain center in an onion architecture in Python

Define a repository interface and an in-memory mock to test domain services without touching infrastructure.

onion-architecture repository-pattern dependency-injection
Python
from abc import ABC, abstractmethod
from dataclasses import dataclass
from typing import Dict, List, Optional


@dataclass
class Order:
    id: int
    customer: str
    items: List[str]
    total: float


class OrderRepository(ABC):
    @abstractmethod
    def find_by_id(self, order_id: int) -> Optional[Order]:
     …
11 0 Open

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PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.

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  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

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