DECOLOG

A lightweight Python logging decorator that automatically logs function calls, arguments, execution time, and exceptions. Provides both console and file logging with configurable verbosity.

Installation

pip install decolog

Quick Start

Basic Usage

from decolog import Logger
import logging

# Initialize logger
logger = Logger(
    app_name="my_app",
    dir_path="./logs",
    log_level=logging.DEBUG,
    console_handler_level=logging.DEBUG,
    file_handler_level=logging.DEBUG
)

# Decorate functions - logs calls automatically
@logger
def add_numbers(a, b):
    return a + b

@logger
def greet(name):
    return f"Hello, {name}!"

# Function calls are automatically logged
result = add_numbers(5, 3)  # Logs: function name, args, execution time
message = greet("World")    # Logs: function name, args, execution time

Per-Function Verbosity Control

Control whether function arguments are truncated in logs:

# Default: arguments are truncated (verbose=False)
@logger
def function1(x, y, z):
    return x + y + z

# Explicit verbose=False (same as default)
@logger(is_verbose=False)
def function2(x, y, z):
    return x + y + z

# Full arguments shown (verbose=True)
@logger(is_verbose=True)
def function3(x, y, z):
    return x + y + z

Features

• Automatic function logging: Logs function name, arguments, execution time
• Exception logging: Automatically logs exceptions with traceback
• Dual output: Logs to both console and file
• Per-function verbosity: Control argument display per function
• Configurable log levels: Set different levels for console and file output
• Daily log rotation: Creates new log files daily

Parameters

Logger Initialization

Logger(
    app_name: str,              # Application name (used in log files)
    dir_path: str | Path,       # Directory for log files
    log_level: int = logging.DEBUG,  # Overall log level
    console_handler_level: int = logging.DEBUG,  # Console log level
    file_handler_level: int = logging.DEBUG      # File log level
)

Decorator Usage

@logger(is_verbose=False)  # Truncate function arguments in logs (default)
@logger(is_verbose=True)   # Show full function arguments in logs

Log Format

Logs follow this format:

YYYY-MM-DD HH:MM:SS|app_name|LOG_LEVEL:message

Example log entry:

2023-11-15 14:30:45|my_app|DEBUG:add_numbers(*(5, 3), **{})
2023-11-15 14:30:45|my_app|DEBUG:executed add_numbers(*(5, 3), **{}) in 0.0001 seconds

Advanced Example

from decolog import Logger
import logging

# Configure logger
logger = Logger(
    app_name="data_processor",
    dir_path="/var/log/myapp",
    console_handler_level=logging.INFO,   # Less verbose console output
    file_handler_level=logging.DEBUG      # Detailed file logs
)

# Decorate multiple functions with different verbosity
@logger
def load_data(file_path):
    # ... implementation ...
    pass

@logger(is_verbose=True)
def process_data(data, config):
    # ... implementation ...
    pass

@logger(is_verbose=False)
def save_results(results, output_path):
    # ... implementation ...
    pass

# All function calls are automatically logged
load_data("input.csv")
process_data(data, config={"param": "value"})
save_results(results, "output.json")