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Modern tooling

uv, ruff, pyproject.toml, packaging, and current Python project workflows.

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Modern tooling easy

How to Build a Chainable Filter Helper in Python

A beginner-friendly dataclass helper that chains filters, uniqueness, and slicing on any sequence, returning a plain list at the end.

dataclass chaining filter
Python
from dataclasses import dataclass
from typing import Callable, Iterator, Sequence, TypeVar

T = TypeVar("T")


@dataclass
class FilterAssistant:
    """Beginner-friendly helper to filter any collection."""

    data: Sequence[T]

    def where(self, predicate: Callable[[T], bool]) -> "FilterAssistant":
        return …
14 0 Open
Modern tooling easy

How to Load and Inspect CSV Data with a Dataclass Helper in Python

This code defines a DataHelper dataclass that reads a CSV file into a list of dictionaries and prints basic dataset information.

csv dataclass pathlib
Python
from pathlib import Path
from dataclasses import dataclass
from typing import Any


@dataclass
class DataHelper:
    """Simple helper for loading and inspecting CSV data."""
    filepath: Path

    def load_csv(self, *, delimiter: str = ",") -> list[dict[str, Any]]:
        """Read CSV into a list of dictionaries."""
…
16 0 Open
Modern tooling easy

How to Load and Inspect Data Files in Python

A beginner-friendly DataLoader dataclass that loads JSON or text files and provides methods to preview and inspect the data.

dataclasses file-io json
Python
from dataclasses import dataclass, field
from pathlib import Path
import json
from typing import Any, Dict, List


@dataclass
class DataLoader:
    """Simple helper to load and inspect data files for beginners."""
    path: Path
    data: Any = field(init=False, default=None)

    def __post_init__(self) -> None:
    …
16 0 Open
Modern tooling easy

How to Mock Fabric Connections in Python for Task Testing

Create a lightweight MockConnection class to replace fabric.Connection and test task functions without SSH.

fabric mocking testing
Python
from fabric import Connection


class MockConnection:
    """Minimal mock of fabric.Connection for task testing."""

    def __init__(self):
        self.commands = []

    def run(self, command, **kwargs):
        self.commands.append(command)
        return f"OK: {command}"


def deploy(conn):
    """Deploy the app:…
14 0 Open

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Modern tooling — Python code examples

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This page collects modern tooling snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.