Logging and debugging are essential when developing applications, as they help us to identify errors and track the flow of our code. In this blog post, we will explore how to enable logging and debugging with Peewee, a lightweight and easy-to-use Python ORM.

Enabling Logging

To enable logging in Peewee, we need to configure the logger and set the log level. Peewee uses the standard Python logging library, so we can utilize its various features.

To begin, let’s import the necessary modules:

import logging
from peewee import *

Next, we can configure the logger and set the log level to debug:

logger = logging.getLogger('peewee')
logger.addHandler(logging.StreamHandler())
logger.setLevel(logging.DEBUG)

This code sets up a logger named peewee and adds a StreamHandler to output log messages to the console. The log level is set to DEBUG, which includes all log levels like INFO, WARNING, ERROR, and CRITICAL. You can adjust the log level based on your needs.

Logging Query Execution

Peewee provides a simple way to log the execution of SQL queries. We can enable query logging by setting the log level specifically for the peewee logger:

logger.setLevel(logging.DEBUG)
logger.setLevel(logging.INFO)  # You can specify a specific log level

Now all SQL queries executed by Peewee will be logged at the specified log level. This is especially useful for debugging and performance optimization.

Customizing the Log Output

Peewee allows us to customize the format and destination of log messages. We can achieve this by configuring the StreamHandler.

For example, to save log messages to a file instead of printing them to the console, we can modify our logger configuration as follows:

file_handler = logging.FileHandler('peewee.log')
logger.addHandler(file_handler)

This code adds a FileHandler to the logger, specifying the file name as peewee.log. Now all log messages will be logged to this file.

To customize the log message format, we can set the format for the StreamHandler or FileHandler:

formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
file_handler.setFormatter(formatter)

This code sets the log message format to include the timestamp, logger name, log level, and the actual log message.

Logging Error Messages

In addition to query execution logging, Peewee allows us to log any error messages arising from database operations.

For example, to log an error message when a database connection fails, we can use a try-except block and the logger object:

try:
    db.connect()
except OperationalError as e:
    logger.error('Could not connect to the database: ' + str(e))

This code attempts to connect to the database, and if the connection fails, an error message is logged with the specific exception details.

Logging error messages can be invaluable when troubleshooting issues in your application.

Conclusion

In this blog post, we explored how to enable logging and debugging with Peewee in Python. We learned how to configure the logger, enable query logging, customize log output, and log error messages.

Logging and debugging are essential tools in the development process, allowing us to track the flow of our code and identify and resolve errors. By utilizing the features provided by Peewee and the Python logging library, we can make the debugging process more efficient and effective.

Happy logging and debugging!