Skip to main content

Konf is a Python package which designed to simplify the use of variables in configuration files. json and yaml supported out of the box.

Project description


Designed to simplify the use of variables in configuration files. Import variables to Python must be easy and reliable!


pip install konf

Running tests:



  • Easy to use

  • JSON and YAML support out of the box

  • Require typing or validation of all input data for human factor prevention

  • Python 2.7, 3+ compatible

  • Unit-tested

  • Custom format of configuration files can be used

For Python data structures validation can be used one of these excellent libs:

For YAML parsing is used a great lib of Kirill Simonov PyYAML

Quick start

Just look at the code.

from konf import Konf

# Filling of variables from config file fruits.yml in k_ object
k_ = Konf('fruits.yml')

# Getting variables from k_. 1st arg is a name of variable (specified in config),
# 2nd can be a type or validator
APPLE = k_('APPLE', basestring)
ORANGE = k_('ORANGE', basestring)

# In the next example is using validator: list, that must contain only objects with
# basestring type (str or unicode)
BASKET_OF_MANDARINS = k_('BASKET', [basestring])

# And dict with two required keys with appropriate types
NAMED_BANANAS = k_('BANANAS', {'yellow': basestring, 'banana2': basestring})

# Other example with grades.json file
k2_ = Konf('grades.json')

DAVID_GRADE = k2_('DAVID', int)
MARIA_GRADE = k2_('MARIA', int)

You can find more details and advanced examples about natural validation on voluptuous or good pages.

Default values

Do you need to use a value if any variable is not contained in a config file? You can use default value.

from konf import Konf

k_ = Konf('extra.yml')

# 3rd arg is a default. If variable STRICT is not contained in config file,
# USE_STRICT will be False
USE_STRICT = k_('STRICT', bool, False)

# You can also use None as default value
WINNER = k_('WINNER', int, None)

# Default values will never be validated, because you forcibly declaring it.
# So, the next example is legit.
SHIFT_TIME = k_('SHIFT', int, complex(42, 42))

Checking not involved variables

Sometimes you want to be sure that all of the variables in a config file are involved and you haven’t forgotten anything. In this situation the check_involved() method can be helpful.

from konf import Konf

k_ = Konf('required.yml')

IMPORTANT_1 = k_('IMPORTANT_1', int)

IMPORTANT_2 = k_('IMPORTANT_2', int)

# If config file contains anything except IMPORTANT_1 and IMPORTANT_2,
# RedundantConfigError will be raised after call of this method!

Default values and check_involved() also working fine together.

from konf import Konf

k_ = Konf('foo.yml')

X = k_('X', int, 0)

Y = k_('Y', int, 0)

# If X and Y doesn't contained in the config file, RedundantConfigError will not be raised,
# just X == 0 and Y == 0

List of supporting Exceptions


Raises when data from config file doesn’t match to the type_or_validator arg


Raises after trying to get variable that not contained in a config file


Raises when config file can’t be read


Raises if third-party parser can’t parse configuration file


Raises if variable loaded not for the first time


Raises if extension of the config is not .yml or .json, and parse_callback arg is not specified


Raises after check_involved() call if any of variables in config file is not involved in the program

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

konf-1.1.2a0.tar.gz (6.1 kB view hashes)

Uploaded source

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Fastly Fastly CDN Google Google Object Storage and Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page