Package: colouredlogs
NOTE: This is a parody of the greatpython-colouredlogsproject
by Peter Odding. Please use that package as I currently have no
plans to maintain this one. All I’ve done iss/color/colour/g.Thecolouredlogspackage enables coloured terminal output for Python’sloggingmodule. TheColouredFormatterclass inherits fromlogging.Formatterand usesANSI escape sequencesto render your logging messages in colour. It uses only
standard colours so it should work on any UNIX terminal. It’s currently tested
on Python 2.6, 2.7, 3.4, 3.5, 3.6 and PyPy. On Windowscolouredlogsautomatically pulls inColouramaas a dependency and enables ANSI escape
sequence translation using Colourama. Here is a screen shot of the demo that is
printed when the commandcolouredlogs--demois executed:Note that the screenshot above includes custom logging levels defined by myverboselogspackage: if you install bothcolouredlogsandverboselogsit
will Just Work (verboselogsis of course not required to usecolouredlogs).InstallationUsageFormat of log messagesEnabling millisecond precisionChanging text styles and coloursColoured output from cronModifying your crontabModifying your Python codeContactLicenseInstallationThecolouredlogspackage is available onPyPIwhich means installation should
be as simple as:$pipinstallcolouredlogsThere’s actually a multitude of ways to install Python packages (e.g. theper
user site-packages directory,virtual environmentsor just installing
system wide) and I have no intention of getting into that discussion here, so
if this intimidates you then read up on your options before returning to these
instructions ;-).UsageHere’s an example of how easy it is to get started:importcolouredlogs,logging# Create a logger object.logger=logging.getLogger(__name__)# By default the install() function installs a handler on the root logger,# this means that log messages from your code and log messages from the# libraries that you use will all show up on the terminal.colouredlogs.install(level='DEBUG')# If you don't want to see log messages from libraries, you can pass a# specific logger object to the install() function. In this case only log# messages originating from that logger will show up on the terminal.colouredlogs.install(level='DEBUG',logger=logger)# Some examples.logger.debug("this is a debugging message")logger.info("this is an informational message")logger.warning("this is a warning message")logger.error("this is an error message")logger.critical("this is a critical message")Format of log messagesTheColouredFormatterclass supports user defined log formats so you can use
any log format you like. The default log format is as follows:%(asctime)s %(hostname)s %(name)s[%(process)d] %(levelname)s %(message)sThis log format results in the following output:2015-10-23 03:32:22 peter-macbook colouredlogs.demo[30462] DEBUG message with level 'debug'
2015-10-23 03:32:23 peter-macbook colouredlogs.demo[30462] VERBOSE message with level 'verbose'
2015-10-23 03:32:24 peter-macbook colouredlogs.demo[30462] INFO message with level 'info'
...You can customize the log format and styling using environment variables as
well as programmatically, please refer to theonline documentationfor
details.Enabling millisecond precisionIf you’re switching fromlogging.basicConfig()tocolouredlogs.install()you may notice that timestamps no longer include milliseconds. This is because
colouredlogs doesn’t output milliseconds in timestamps unless you explicitly
tell it to. There are three ways to do that:The easy way is to pass themillisecondsargument tocolouredlogs.install():colouredlogs.install(milliseconds=True)This became supported inrelease 7.1(due to#16).Alternatively you can change the log formatto include ‘msecs’:%(asctime)s,%(msecs)03d %(hostname)s %(name)s[%(process)d] %(levelname)s %(message)sHere’s what the call tocolouredlogs.install()would then look like:colouredlogs.install(fmt='%(asctime)s,%(msecs)03d %(hostname)s %(name)s[%(process)d] %(levelname)s %(message)s')Customizing the log format also enables you to change the delimiter that
separates seconds from milliseconds (the comma above). This became possible
inrelease 3.0which added support for user defined log formats.If the use of%(msecs)disn’t flexible enough you can instead add%fto the date/time format, it will be replaced by the value of%(msecs)03d.
Support for the%fdirective was added torelease 9.3(due to#45).Changing text styles and coloursThe online documentation containsan example of customizing the text styles and
colours.Coloured output from cronWhencolouredlogsis used in acronjob, the output that’s e-mailed to you by
cron won’t contain any ANSI escape sequences becausecolouredlogsrealizes
that it’s not attached to an interactive terminal. If you’d like to have colours
e-mailed to you by cron there are two ways to make it happen:Modifying your crontabModifying your Python codeModifying your crontabHere’s an example of a minimal crontab:MAILTO="your-email-address@here"
CONTENT_TYPE="text/html"
* * * * * root colouredlogs --to-html your-commandThecolouredlogsprogram is installed when you install thecolouredlogsPython package. When you executecolouredlogs--to-htmlyour-commandit runsyour-commandunder the external programscript(you need to have this
installed). This makesyour-commandthink that it’s attached to an
interactive terminal which means it will output ANSI escape sequences which
will then be converted to HTML by thecolouredlogsprogram. Yes, this is a
bit convoluted, but it works great :-)Modifying your Python codeTheColouredCronMailerclass provides a context manager that automatically
enables HTML output when the$CONTENT_TYPEvariable has been correctly set
in the crontab.This requires mycapturerpackage which you can install usingpip install 'colouredlogs[cron]'. The[cron]extra will pull incapturer2.4 or newer
which is required to capture the output while silencing it - otherwise you’d
get duplicate output in the emails sent bycron.The context manager can also be used to retroactively silence output that has
already been produced, this can be useful to avoid spammy cron jobs that have
nothing useful to do but still email their output to the system administrator
every few minutes :-).ContactThe latest version ofcolouredlogsis available onPyPIandGitHub. Theonline documentationis available on Read The Docs and includes achangelog. For bug reports please create an issue onGitHub. If you have
questions, suggestions, etc. feel free to send me an e-mail atpeter@peterodding.com.LicenseThis software is licensed under theMIT license.© 2018 Peter Odding.