Modern tooling
uv, ruff, pyproject.toml, packaging, and current Python project workflows.
How to Mock CLI Output in Typer with unittest.mock
Mock and capture Typer CLI output using unittest.mock.patch and io.StringIO for testing command-line applications.
import typer
from unittest.mock import patch
import io
app = typer.Typer()
@app.command()
def greet(name: str, age: int = 18, uppercase: bool = False):
"""Greet a person with optional formatting."""
message = f"Hello {name}, age {age}"
if uppercase:
message = message.upper()
typer.echo(messag…Mocking loguru for Structured Logging in Python
Simulate loguru's structured logging with a custom mock that captures JSON-formatted log entries with bound context.
import json
import sys
from io import StringIO
from unittest.mock import patch
def mock_loguru():
# Simulate a structured logger with context binding
class StructuredLogger:
def __init__(self):
self.context = {}
def bind(self, **kwargs):
logger = StructuredLogger()
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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.