dlf4p — Dexoron Logging Framework for Python

dlf4p is a lightweight and convenient logger for Python inspired by SLF4J. It provides a simple API for logging messages with support for log levels, colored console output, timestamps, and file logging.

The project is being developed as part of the DLF (Dexoron Logging Framework) family, with plans for implementations in other programming languages.

GitLab repository: https://gitlab.com/dexoron/dlf4p PyPi project: https://pypi.org/project/dlf4p

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Features

• Log levels: DEBUG, INFO, SUCCESS, WARNING, ERROR, FATAL, EXCEPTION
• Colored console output
• Timestamp support
• Prefix support (e.g., module or component name)
• File logging
• Configuration via dlf_settings.json
• Traceback output for exceptions
• Exception logging helper: exception()
• Lightweight and with no external dependencies

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Installation

Install from PyPI:

pip install dlf4p

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Quick Start

import dlf4p as dlf

dlf.info("Application started", "Main")
dlf.success("Server successfully started", "Server")
dlf.warning("Slow response", "API")
dlf.error("Database connection error", "Database")
dlf.fatal("Critical error", "System")

try:
    1 / 0
except Exception as e:
    dlf.error("Division failed", "Math", exc=e)
    dlf.exception("Unhandled error", "Math", exc=e)

Console output:

[14:24:56] [Main/INFO]: Application started
[14:24:56] [Server/SUCCESS]: Server successfully started
[14:24:56] [API/WARNING]: Slow response
[14:24:56] [Database/ERROR]: Database connection error
[14:24:56] [System/FATAL]: Critical error
[14:24:56] [Math/ERROR]: Division failed
Traceback (most recent call last):
  File "/home/probrovova/project/dlf-py/test/main.py", line 30, in <module>
    1 / 0
ZeroDivisionError: division by zero
[14:24:56] [Math/EXCEPTION]: Unhandled error
Traceback (most recent call last):
  File "/home/probrovova/project/dlf-py/test/main.py", line 30, in <module>
    1 / 0
ZeroDivisionError: division by zero

Logger class example:

import dlf4p as dlf

log = dlf.Logger("Main")
log.info("Application started")

log = dlf.Logger("Core")
log.setLevel(2)  # SUCCESS and higher
log.info("Core module initialized")
log.success("Submodule loaded successfully")
log.warning("Disabled System modules")

try:
    raise ValueError("Bad value")
except Exception as e:
    log.exception("Something went wrong", exc=e)

Console output:

[14:26:59] [Main/INFO]: Application started
[14:26:59] [Core/INFO]: Log level set to SUCCESS
[14:26:59] [Core/SUCCESS]: Submodule loaded successfully
[14:26:59] [Core/WARNING]: Disabled System modules
[14:26:59] [Core/EXCEPTION]: Something went wrong
Traceback (most recent call last):
  File "/home/probrovova/project/dlf-py/test/main.py", line 31, in <module>
    raise ValueError("Bad value")
ValueError: Bad value

Logs are saved to a file without ANSI color codes. Traceback output uses the provided exc object.

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Configuration

Configuration is loaded from dlf_settings.json in the current working directory. If the file does not exist, it will be created with defaults on first import.

Example dlf_settings.json:

{
  "custom_prefix": "",
  "use_time": true,
  "use_color": true,
  "use_file_logging": true,
  "log_filename": "log-{get_data}-{get_time}.log"
}

Fields:

• custom_prefix — custom format string (empty string uses default format)
• use_time — enable or disable timestamps
• use_color — enable or disable colors
• use_file_logging — enable writing logs to a file
• log_filename — template for log file name, supports {get_data} and {get_time}

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Run Example

From the project root:

python3 -m test.main

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Testing

Run automated tests with pytest:

python -m pytest -q

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Philosophy

dlf4p is inspired by SLF4J (Simple Logging Facade for Java) and aims to:

• provide a simple and unified logging interface
• remain minimalistic
• have no external dependencies
• be easily extensible to other programming languages

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License

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

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Author

Dexoron

GitLab: https://gitlab.com/dexoron GitHub: https://github.com/dexoron Website: https://dexoron.su

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Project Links

Changelog: CHANGELOG
Contributing guide: CONTRIBUTING.md GitLab repository: https://gitlab.com/dexoron/dlf4p PyPi project: https://pypi.org/project/dlf4p

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dlf4p — a simple logger today, a full logging framework tomorrow.