colorlog.ColoredFormatter
is a formatter for use with Python's logging
module that outputs records using terminal colors.
Install from PyPI with:
pip install colorlog
Several Linux distributions provide offical packages (Debian, Gentoo, OpenSuse and Ubuntu), and others have user provided packages (Arch AUR, BSD ports, Conda, Fedora packaging scripts).
import colorlog
handler = colorlog.StreamHandler()
handler.setFormatter(colorlog.ColoredFormatter(
'%(log_color)s%(levelname)s:%(name)s:%(message)s'))
logger = colorlog.getLogger('example')
logger.addHandler(handler)
The ColoredFormatter
class takes several arguments:
format
: The format string used to output the message (required).datefmt
: An optional date format passed to the base class. Seelogging.Formatter
.reset
: Implicitly adds a color reset code to the message output, unless the output already ends with one. Defaults toTrue
.log_colors
: A mapping of record level names to color names. The defaults can be found incolorlog.default_log_colors
, or the below example.secondary_log_colors
: A mapping of names tolog_colors
style mappings, defining additional colors that can be used in format strings. See below for an example.style
: Available on Python 3.2 and above. Seelogging.Formatter
.
Color escape codes can be selected based on the log records level, by adding parameters to the format string:
log_color
: Return the color associated with the records level.<name>_log_color
: Return another color based on the records level if the formatter has secondary colors configured (seesecondary_log_colors
below).
Multiple escape codes can be used at once by joining them with commas when
configuring the color for a log level (but can't be used directly in the format
string). For example, black,bg_white
would use the escape codes for black
text on a white background.
The following escape codes are made available for use in the format string:
{color}
,fg_{color}
,bg_{color}
: Foreground and background colors.bold
,bold_{color}
,fg_bold_{color}
,bg_bold_{color}
: Bold/bright colors.reset
: Clear all formatting (both foreground and background colors).
The available color names are black
, red
, green
, yellow
, blue
,
purple
, cyan
and white
.
The following code creates a ColoredFormatter
for use in a logging setup,
using the default values for each argument.
from colorlog import ColoredFormatter
formatter = ColoredFormatter(
"%(log_color)s%(levelname)-8s%(reset)s %(blue)s%(message)s",
datefmt=None,
reset=True,
log_colors={
'DEBUG': 'cyan',
'INFO': 'green',
'WARNING': 'yellow',
'ERROR': 'red',
'CRITICAL': 'red,bg_white',
},
secondary_log_colors={},
style='%'
)
Secondary log colors are a way to have more than one color that is selected
based on the log level. Each key in secondary_log_colors
adds an attribute
that can be used in format strings (message
becomes message_log_color
), and
has a corresponding value that is identical in format to the log_colors
argument.
The following example highlights the level name using the default log colors,
and highlights the message in red for error
and critical
level log messages.
from colorlog import ColoredFormatter
formatter = ColoredFormatter(
"%(log_color)s%(levelname)-8s%(reset)s %(message_log_color)s%(message)s",
secondary_log_colors={
'message': {
'ERROR': 'red',
'CRITICAL': 'red'
}
}
)
With dictConfig
logging.config.dictConfig({
'formatters': {
'colored': {
'()': 'colorlog.ColoredFormatter',
'format': "%(log_color)s%(levelname)-8s%(reset)s %(blue)s%(message)s"
}
},
...
})
A full example dictionary can be found in tests/test_colorlog.py
.
With fileConfig
...
[formatters]
keys=color
[formatter_color]
class=colorlog.ColoredFormatter
format=%(log_color)s%(levelname)-8s%(reset)s %(bg_blue)s[%(name)s]%(reset)s %(message)s from fileConfig
datefmt=%m-%d %H:%M:%S
An instance of ColoredFormatter created with those arguments will then be used
by any handlers that are configured to use the color
formatter.
A full example configuration can be found in tests/test_config.ini
.
ColoredFormatter will work with custom log levels added with
logging.addLevelName
:
import logging, colorlog
TRACE = 5
logging.addLevelName(TRACE, 'TRACE')
formatter = colorlog.ColoredFormatter(log_colors={'TRACE': 'yellow'})
handler = logging.StreamHandler()
handler.setFormatter(formatter)
logger = logging.getLogger('example')
logger.addHandler(handler)
logger.setLevel('TRACE')
logger.log(TRACE, 'a message using a custom level')
colorlog works on Python 2.6 and above, including Python 3.
On Windows, requires colorama to work properly. A dependancy on colorama is
included as an optional package dependancy - depending on colorlog[windows]
instead of colorlog
will ensure it is included when installing.
Tests similar to the above examples are found in tests/test_colorlog.py
.
tox
will run the tests under all compatible python versions.
Copyright (c) 2012 Sam Clements [email protected]
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.