Salt Coding Style

Salt is developed with a certain coding style, while the style is dominantly PEP 8 it is not completely PEP 8. It is also noteworthy that a few development techniques are also employed which should be adhered to. In the end, the code is made to be "Salty".

Most importantly though, we will accept code that violates the coding style and KINDLY ask the contributor to fix it, or go ahead and fix the code on behalf of the contributor. Coding style is NEVER grounds to reject code contributions, and is never grounds to talk down to another member of the community (There are no grounds to treat others without respect, especially people working to improve Salt)!!


Most Salt style conventions are codified in Salt's .testing.pylintrc file. Salt's pylint file has two dependencies: pylint and saltpylint. You can install these dependencies with pip:

pip install pylint
pip install saltpylint

The .testing.pylintrc file is found in the root of the Salt project and can be passed as an argument to the pylint program as follows:

pylint --rcfile=/path/to/salt/.testing.pylintrc salt/dir/to/lint


There are two pylint files in the salt directory. One is the .pylintrc file and the other is the .testing.pylintrc file. The tests that run in Jenkins against GitHub Pull Requests use .testing.pylintrc. The testing.pylintrc file is a little less strict than the .pylintrc and is used to make it easier for contributors to submit changes. The .pylintrc file can be used for linting, but the testing.pylintrc is the source of truth when submitting pull requests.


Variables should be a minimum of three characters and should provide an easy-to-understand name of the object being represented.

When keys and values are iterated over, descriptive names should be used to represent the temporary variables.

Multi-word variables should be separated by an underscore.

Variables which are two-letter words should have an underscore appended to them to pad them to three characters.


Salt follows a few rules when formatting strings:

Single Quotes

In Salt, all strings use single quotes unless there is a good reason not to. This means that docstrings use single quotes, standard strings use single quotes etc.:

def foo():
    A function that does things
    name = 'A name'
    return name

Formatting Strings

All strings which require formatting should use the .format string method:

data = 'some text'
more = '{0} and then some'.format(data)

Make sure to use indices or identifiers in the format brackets, since empty brackets are not supported by python 2.6.

Please do NOT use printf formatting.

Docstring Conventions

Docstrings should always add a newline, docutils takes care of the new line and it makes the code cleaner and more vertical:


def bar():
    Here lies a docstring with a newline after the quotes and is the salty
    way to handle it! Vertical code is the way to go!


def baz():
    '''This is not ok!'''

When adding a new function or state, where possible try to use a versionadded directive to denote when the function or state was added.

def new_func(msg=''):
    .. versionadded:: 0.16.0

    Prints what was passed to the function.

    msg : None
        The string to be printed.
    print msg

If you are uncertain what version should be used, either consult a core developer in IRC or bring this up when opening your pull request and a core developer will add the proper version once your pull request has been merged. Bugfixes will be available in a bugfix release (i.e. 0.17.1, the first bugfix release for 0.17.0), while new features are held for feature releases, and this will affect what version number should be used in the versionadded directive.

Similar to the above, when an existing function or state is modified (for example, when an argument is added), then under the explanation of that new argument a versionadded directive should be used to note the version in which the new argument was added. If an argument's function changes significantly, the versionchanged directive can be used to clarify this:

def new_func(msg='', signature=''):
    .. versionadded:: 0.16.0

    Prints what was passed to the function.

    msg : None
        The string to be printed. Will be prepended with 'Greetings! '.

    .. versionchanged:: 0.17.1

    signature : None
        An optional signature.

    .. versionadded 0.17.0
    print 'Greetings! {0}\n\n{1}'.format(msg, signature)


Dictionaries should be initialized using {} instead of dict().

See here for an in-depth discussion of this topic.


Salt code prefers importing modules and not explicit functions. This is both a style and functional preference. The functional preference originates around the fact that the module import system used by pluggable modules will include callable objects (functions) that exist in the direct module namespace. This is not only messy, but may unintentionally expose code python libs to the Salt interface and pose a security problem.

To say this more directly with an example, this is GOOD:

import os

def minion_path():
    path = os.path.join(self.opts['cachedir'], 'minions')
    return path

This on the other hand is DISCOURAGED:

from os.path import join

def minion_path():
    path = join(self.opts['cachedir'], 'minions')
    return path

The time when this is changed is for importing exceptions, generally directly importing exceptions is preferred:

This is a good way to import exceptions:

from salt.exceptions import CommandExecutionError

Absolute Imports

Although absolute imports seems like an awesome idea, please do not use it. Extra care would be necessary all over salt's code in order for absolute imports to work as supposed. Believe it, it has been tried before and, as a tried example, by renaming salt.modules.sysmod to salt.modules.sys, all other salt modules which needed to import sys would have to also import absolute_import, which should be avoided.


An exception to this rule is the absolute_import from __future__ at the top of each file within the Salt project. This import is necessary for Py3 compatibility. This particular import looks like this:

from __future__ import absolute_import

This import is required for all new Salt files and is a good idea to add to any custom states or modules. However, the practice of avoiding absolute imports still applies to all other cases as to avoid a name conflict.

Vertical is Better

When writing Salt code, vertical code is generally preferred. This is not a hard rule but more of a guideline. As PEP 8 specifies, Salt code should not exceed 79 characters on a line, but it is preferred to separate code out into more newlines in some cases for better readability:

import os


Where there are more line breaks, this is also apparent when constructing a function with many arguments, something very common in state functions for instance:

def managed(name,


Making function and class definitions vertical is only required if the arguments are longer then 80 characters. Otherwise, the formatting is optional and both are acceptable.

Line Length

For function definitions and function calls, Salt adheres to the PEP-8 specification of at most 80 characters per line.

Non function definitions or function calls, please adopt a soft limit of 120 characters per line. If breaking the line reduces the code readability, don't break it. Still, try to avoid passing that 120 characters limit and remember, vertical is better... unless it isn't


Some confusion exists in the python world about indenting things like function calls, the above examples use 8 spaces when indenting comma-delimited constructs.

The confusion arises because the pep8 program INCORRECTLY flags this as wrong, where PEP 8, the document, cites only using 4 spaces here as wrong, as it doesn't differentiate from a new indent level.


def managed(name,


def managed(name,

Lining up the indent is also correct:

def managed(name,

This also applies to function calls and other hanging indents.

pep8 and Flake8 (and, by extension, the vim plugin Syntastic) will complain about the double indent for hanging indents. This is a known conflict between pep8 (the script) and the actual PEP 8 standard. It is recommended that this particular warning be ignored with the following lines in ~/.config/flake8:

ignore = E226,E241,E242,E126

Make sure your Flake8/pep8 are up to date. The first three errors are ignored by default and are present here to keep the behavior the same. This will also work for pep8 without the Flake8 wrapper -- just replace all instances of 'flake8' with 'pep8', including the filename.

Code Churn

Many pull requests have been submitted that only churn code in the name of PEP 8. Code churn is a leading source of bugs and is strongly discouraged. While style fixes are encouraged they should be isolated to a single file per commit, and the changes should be legitimate, if there are any questions about whether a style change is legitimate please reference this document and the official PEP 8 ( document before changing code. Many claims that a change is PEP 8 have been invalid, please double check before committing fixes.