burin 0.2.0

Logging with added features and convenience.

Burin Logging Utility

Burin (/ˈbyʊər ɪn, ˈbɜr-/byoor-in, bur-/) is a logging library that is meant to add features and simplify usage compared to the Python standard library logging package. It can be used as a direct replacement in most cases.

Full Burin documentation is available at Read the Docs.

Currently Python 3.7, 3.8, 3.9, 3.10, 3.11, and 3.12 are all supported. There are no dependencies or additional requirements for Burin and it should work on any platform that Python does.

Warning

Python 3.7 support is deprecated and will be removed in a future release.

An important aspect of Burin is an easy migration that allows changing from the logging package to Burin without anything breaking in most use cases. While class names may need to be changed this generally should work well. Although some situations may require other small changes due to the added features of Burin.

Using Burin to replace logging use in a program can be done gradually or all at once. Burin should not intefere with logging usage as its internal references are all managed independently. However; it’s best to ensure that they are not trying to log to the same file as this may cause issues.

Note

While some classes in Burin inherit from classes in the Python standard logging package they cannot be used interchangeably.

Using classes from logging in Burin or vice-versa may cause exceptions or other issues.

Note

Burin is still in early development and may change in backwards incompatible ways between minor release versions. This should be rare as general compatibility with logging is desired to ease switching, but it is a good idea check the release notes when upgrading between minor (0.X.0) releases.

What’s Different in Burin?

The following make up the current major differences compared to the Python standard logging module.

• Extra arguments and changes to basic_config allow it to be used in more situations and when setting up common logging configurations.

• Built-in support for deferred formatting of str.format and string.Template style logging messages.

• Library level logging calls (eg. burin.log) can specify a logger to use other than the root logger, so calling get_logger isn’t necessary first.

• Logging features from newer versions of Python (eg. logAsyncioTasks in 3.12) are implemented in Burin and available in all supported Python versions.

• Everything that should be needed is available at the top level of the library; no more extra imports of logging.handlers and logging.config.

• Multiple log record factory classes are supported at the same time, and which is used can be set per logger instance to allow for greater customisation.

• BurinLoggerAdapter instances will merge extra values from logging calls with the pre-set values from instantiation; nesting built-in adapters can actually be useful now.

• All handlers within Burin support a level parameter during initialization so an extra call BurinHandler.set_level isn’t needed

• BurinSocketHandler and BurinDatagramHandler by default use pickling protocol version 4 instead of 1. This can be set to a different protocol version when creating the handler.

• All methods and functions are underscore_separated, but camelCase aliases are available for an easier transition from the standard library.

• Logging configuration attributes logMultiproccessing, logProcesses, logThreads, and raiseExceptions are on a burin.config object instead of directly on the module.

• Deprecated methods such as fatal and warn are not implemented.

There are several other differences which are more minor or are internal to Burin and not documented in this list. If you are going to create subclasses or use internal classes and methods, then just make sure to read the documentation or docstrings within the code.

What Can’t Burin Do?

Burin is still in early development and does not yet support some use cases that are supported by Python logging. These features are planned to be implemented before Burin reaches its first stable major (1.0.0) release.

• Advanced configuration functions like those from logging.config (dictConfig, fileConfig, and listen) are not yet implemented.

• Custom log levels are not yet supported.

Using Burin

Below are a few examples of using the features of Burin. Read through the rest of the documentation to see the full information on the functionality of Burin.

Note

All Burin functions and methods are underscore_separated, however to ease changing from the standard library they all also have camelCase aliases.

Throughout this documentation the underscore_separated names are used, but everytime you see a function or method call in Burin just remember that the camelCase name (like what is in logging) will also work.

Burin can be imported and used similar to the logging standard libary package.

import burin
burin.basic_config()
logger = burin.get_logger()
logger.info("I am a log message.")

What is above would do the exact same thing with both Burin and logging.

A Not So “Basic” Config

However compared to the standard logging package; using Burin can be much simpler for certain things, or even allow some functionality that would otherwise require custom wrapper utilities or overridding logging subclasses.

For example a common logging setup may be to output info level logs to a rotating file with a specific format, and also output warning level logs to sys.stderr in a different format.

With Burin setting this up can be accomplished with 2 imports and 1 call to basic_config.

import sys
import burin
burin.basic_config(filename="prog.log", filelevel="INFO", filerotate=True,
                   fileformat="{asctime} - {levelname} :{name}: {message}",
                   filerotatesize=1048576, filerotatecount=9, level="INFO",
                   stream=sys.stderr, streamlevel="WARNING",
                   streamformat="{levelname}: {message}", style="{")

Whereas with logging this takes 3 imports and 12 lines.

import sys
import logging
from logging.handlers import RotatingFileHandler
fileForm = logging.Formatter("{asctime} - {levelname} :{name}: {message}",
                             style="{")
fileHand = RotatingFileHandler("prog.log", maxBytes=1048576, backupCount=9)
fileHand.setFormatter(fileForm)
fileHand.setLevel("INFO")
streamForm = logging.Formatter("{levelname}: {message}", style="{")
streamHand = logging.StreamHandler(sys.stderr)
streamHand.setFormatter(streamForm)
streamHand.setLevel("WARNING")
rootLogger = logging.getLogger()
rootLogger.addHandler(fileHand)
rootLogger.addHandler(streamHand)
rootLogger.setLevel("INFO")

Deferred Formatting Styles

Burin also supports deferred formatting with log messages using str.format and string.Template style strings, as well as the ‘%’ style formatting that the standard library does. Which formatting is used is set by the msgStyle property on a logger which can also be specified when calling get_logger.

formatLogger = burin.get_logger("formatLogger", "{")
formatLogger.debug("This is a {} event in {}", "DEBUG", "Burin")
templateLogger = burin.get_logger("templateLogger", msgStyle="$")
templateLogger.debug("This is a ${lvl} event in ${prog}", lvl="DEBUG",
                     prog="Burin")

Setting this on the root logger will set the default style for new loggers as well.

rootLogger = burin.get_logger(msgStyle="{")
newLogger = burin.get_logger("new")
newLogger.debug("This is a {lvl} event in {prog}", lvl="DEBUG",
                prog="Burin")

Deferred formatting means that all of the extra formatting is only done if a message will be logged, so this can be more efficient than doing the formatting on the string beforehand.

For a bit more information about the deferred logging see BurinLogger.log.

Customisable Log Records

Setting the msgStyle of a logger actually sets the log record factory that is used. While the default built-in factories are focused on formatting, you can actually add any other custom factories that may be useful in your program. These factories can then just be used where needed instead of for all log messages as in the standard library.

This can be incredibly useful when you need a log to display values in a specific way, but only want that extra processing to run if the log message will actually be output.

To add your own factory simply create a subclass of BurinLogRecord and then set it to a msgStyle with set_log_record_factory.

class HexRecord(burin.BurinLogRecord):
    """
    Converts all int values to hex strings for log output.
    """

    def get_message(self):
        msg = str(self.msg)
        if self.args or self.kwargs:
            hexArgs = []
            hexKwargs = {}

            for eachArg in self.args:
                if isinstance(eachArg, int):
                    eachArg = hex(eachArg)
                hexArgs.append(eachArg)

            for eachKey, eachValue in self.kwargs.items():
                if isinstance(eachValue, int):
                    eachValue = hex(eachValue)
                hexKwargs[eachKey] = eachValue

            msg = msg.format(*hexArgs, **hexKwargs)
        return msg

burin.set_log_record_factory(HexRecord, "hex")

In this example you would now be able to use hex as a msgStyle for any loggers where you want int args and kwargs converted to a hexadecimal string when the log message is output.