logcore 0.1.3

A production-ready structured logging library for Python

LogCore 🔥

A production-ready logging library for Python

LogCore provides a simple, structured, and extensible logging solution that works seamlessly for both small scripts and large microservices. It's designed as a drop-in alternative to Python's built-in logging with a focus on developer experience, observability, and production readiness.

✨ Features

• 🚀 Simple API: Single entrypoint with intuitive configuration
• 📊 Structured Logging: JSON and human-readable output formats
• 🔗 Correlation IDs: Built-in request tracing support
• ⏱️ Built-in Timing: Context managers for performance monitoring
• 🛡️ Security: Automatic redaction of sensitive fields
• 📁 File Rotation: Configurable log rotation and archival
• 🎨 Colorized Output: Beautiful console logging with colors
• ⚡ Async Support: Safe for asyncio applications
• 🧵 Thread-safe: Concurrent logging without issues
• 🌍 Environment Configuration: Configure via environment variables

🚀 Quick Start

Installation

pip install logcore

For colored output support:

pip install logcore[colors]

Basic Usage

from logcore import get_logger

# Create a logger
log = get_logger("myapp", level="INFO", json=True)

# Simple logging
log.info("Application started")
log.error("Something went wrong")

# Structured logging with extra fields
log.info("User login", user="alice", role="admin", success=True)

# Exception logging with automatic traceback
try:
    1 / 0
except Exception:
    log.exception("Division failed")

📖 Documentation

Configuration Options

LogCore can be configured through code or environment variables:

from logcore import get_logger

log = get_logger(
    name="myapp",              # Logger name
    level="INFO",              # DEBUG, INFO, WARNING, ERROR, CRITICAL
    json=True,                 # JSON output (False for human-readable)
    file="/path/to/app.log",   # Optional file logging
    correlation_id="req-123",  # Optional correlation ID
    max_file_size=10*1024*1024, # 10MB file size limit
    backup_count=5,            # Keep 5 backup files
    redact_fields={"password", "secret"}  # Fields to redact
)

Environment Variables

Set configuration via environment variables:

export LOGCORE_LEVEL=DEBUG
export LOGCORE_JSON=true
export LOGCORE_FILE=/var/log/app.log
export LOGCORE_CORRELATION_ID=req-abc-123
export LOGCORE_REDACT_FIELDS=password,token,secret

Output Formats

JSON Format

{
  "timestamp": "2025-01-15T10:30:45.123456",
  "level": "INFO",
  "logger": "myapp",
  "message": "User login",
  "correlation_id": "req-123",
  "user": "alice",
  "success": true
}

Human-Readable Format

2025-01-15 10:30:45.123 INFO     myapp [cid=req-123]: User login user=alice success=true

Advanced Features

Correlation IDs for Request Tracing

from logcore import get_logger

log = get_logger("api")

# Set correlation ID for the entire request context
with log.with_correlation_id("req-abc-123"):
    log.info("Processing request")
    process_request()
    log.info("Request completed")

Performance Timing

# Measure execution time automatically
with log.time("database_query", level="DEBUG"):
    result = expensive_database_operation()

# Outputs:
# Starting database_query
# Completed database_query duration_ms=234.56

Exception Handling

try:
    risky_operation()
except Exception as e:
    log.exception("Operation failed", operation="risky_operation", user_id=123)
    # Automatically includes full traceback

Sensitive Data Redaction

# Configure fields to automatically redact
log = get_logger("secure", redact_fields={"password", "token", "ssn"})

log.info("User data", username="alice", password="secret123", role="admin")
# Output: ... username=alice password=[REDACTED] role=admin

File Logging with Rotation

log = get_logger(
    "myapp",
    file="/var/log/myapp.log",
    max_file_size=10 * 1024 * 1024,  # 10MB
    backup_count=5                    # Keep 5 old files
)

Files are automatically rotated:

• myapp.log (current)
• myapp.log.1 (previous)
• myapp.log.2 (older)
• etc.

Async Support

LogCore is fully compatible with asyncio:

import asyncio
from logcore import get_logger

async def main():
    log = get_logger("async_app")

    # Correlation IDs work across await boundaries
    with log.with_correlation_id():
        log.info("Starting async operation")
        await some_async_task()
        log.info("Async operation completed")

    # Async timing context manager
    async with log.time("async_operation"):
        await another_async_task()

asyncio.run(main())

Integration with Web Frameworks

Flask Example

from flask import Flask, request, g
from logcore import get_logger
import uuid

app = Flask(__name__)
log = get_logger("webapp")

@app.before_request
def before_request():
    g.correlation_id = request.headers.get('X-Correlation-ID', str(uuid.uuid4()))

@app.after_request
def after_request(response):
    with log.with_correlation_id(g.correlation_id):
        log.info(
            "Request completed",
            method=request.method,
            path=request.path,
            status_code=response.status_code,
            duration_ms=...  # Add timing logic
        )
    return response

@app.route('/users/<user_id>')
def get_user(user_id):
    with log.with_correlation_id(g.correlation_id):
        log.info("Fetching user", user_id=user_id)
        # ... your logic here

FastAPI Example

from fastapi import FastAPI, Request
from logcore import get_logger
import time
import uuid

app = FastAPI()
log = get_logger("api")

@app.middleware("http")
async def logging_middleware(request: Request, call_next):
    correlation_id = request.headers.get("x-correlation-id", str(uuid.uuid4()))
    start_time = time.time()

    with log.with_correlation_id(correlation_id):
        log.info("Request started", method=request.method, url=str(request.url))

        response = await call_next(request)

        duration = (time.time() - start_time) * 1000
        log.info(
            "Request completed",
            status_code=response.status_code,
            duration_ms=round(duration, 2)
        )

    response.headers["x-correlation-id"] = correlation_id
    return response

🆚 Comparison with Other Libraries

vs. Built-in logging

Feature	LogCore	Built-in logging
Setup complexity	⭐⭐⭐⭐⭐ Single line	⭐⭐ Complex setup
Structured logging	⭐⭐⭐⭐⭐ Built-in	⭐⭐ Manual implementation
JSON output	⭐⭐⭐⭐⭐ Automatic	⭐⭐ Custom formatter needed
Correlation IDs	⭐⭐⭐⭐⭐ Built-in	⭐ Custom context needed
Security	⭐⭐⭐⭐⭐ Auto-redaction	⭐ Manual filtering
Colors	⭐⭐⭐⭐⭐ Auto-detected	⭐⭐ Third-party needed

vs. loguru

Feature	LogCore	Loguru
Production focus	⭐⭐⭐⭐⭐ Enterprise-ready	⭐⭐⭐⭐ Great for development
Correlation IDs	⭐⭐⭐⭐⭐ Built-in context	⭐⭐ Manual binding
Security	⭐⭐⭐⭐⭐ Auto-redaction	⭐⭐ Manual filtering
Async support	⭐⭐⭐⭐⭐ Context-aware	⭐⭐⭐ Basic support
Performance	⭐⭐⭐⭐ Good	⭐⭐⭐⭐⭐ Excellent
Ecosystem	⭐⭐⭐⭐⭐ Standard logging	⭐⭐⭐ Custom approach

🛠️ Development

Setup

git clone https://github.com/SarkarRana/logcore.git
cd logcore

# Install development dependencies
pip install -e ".[dev]"

# Install pre-commit hooks
pre-commit install

Running Tests

# Run all tests
pytest

# Run with coverage
pytest --cov=logcore

# Run specific test categories
pytest -m "not slow"          # Skip slow tests
pytest -m integration         # Run integration tests only

Code Quality

# Format code
black logcore tests
isort logcore tests

# Lint
flake8 logcore tests

# Type checking
mypy logcore

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🤝 Contributing

Contributions are welcome! Please read our Contributing Guide for details on our code of conduct and the process for submitting pull requests.

🎯 Roadmap

• Performance Optimizations: Async batching, lazy formatting
• Integrations: OpenTelemetry, Sentry, DataDog
• Advanced Features: Log sampling, rate limiting
• Cloud Native: Kubernetes-friendly output formats
• Monitoring: Health checks and metrics endpoints

💖 Support

If you find LogForge useful, please consider:

• ⭐ Starring the repository
• 🐛 Reporting bugs and issues
• 💡 Suggesting new features
• 📖 Improving documentation
• 💻 Contributing code

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