Configuration

*************

Naming Styles

=============

Pylint recognizes a number of different name types internally. With a

few exceptions, the type of the name is governed by the location the

assignment to a name is found in, and not the type of object assigned.

"module"

Module and package names, same as the file names.

"const"

Module-level constants, any variable defined at module level that

is not bound to a class object.

"class"

Names in "class" statements, as well as names bound to class

objects at module level.

"function"

Functions, toplevel or nested in functions or methods.

"method"

Methods, functions defined in class bodies. Includes static and

class methods.

"attr"

Attributes created on class instances inside methods.

"argument"

Arguments to any function type, including lambdas.

"variable"

Local variables in function scopes.

"class-attribute"

Attributes defined in class bodies.

"inlinevar"

Loop variables in list comprehensions and generator expressions.

For each naming style, a separate regular expression matching valid

names of this type can be defined. By default, the regular expressions

will enforce PEP8 names.

Regular expressions for the names are anchored at the beginning, any

anchor for the end must be supplied explicitly. Any name not matching

the regular expression will lead to an instance of "invalid-name".

--module-rgx=<regex>

Default value: "[a-z_][a-z0-9_]{2,30}$"

--const-rgx=<regex>

Default value: "[a-z_][a-z0-9_]{2,30}$"

--class-rgx=<regex>

Default value: "'[A-Z_][a-zA-Z0-9]+$"

--function-rgx=<regex>

Default value: "[a-z_][a-z0-9_]{2,30}$"

--method-rgx=<regex>

Default value: "[a-z_][a-z0-9_]{2,30}$"

--attr-rgx=<regex>

Default value: "[a-z_][a-z0-9_]{2,30}$"

--argument-rgx=<regex>

Default value: "[a-z_][a-z0-9_]{2,30}$"

--variable-rgx=<regex>

Default value: "[a-z_][a-z0-9_]{2,30}$"

--class-attribute-rgx=<regex>

Default value: "([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$"

--inlinevar-rgx=<regex>

Default value: "[A-Za-z_][A-Za-z0-9_]*$"

Multiple Naming Styles

----------------------

Large code bases that have been worked on for multiple years often

exhibit an evolution in style as well. In some cases, modules can be

in the same package, but still have different naming style based on

the stratum they belong to. However, intra-module consistency should

still be required, to make changes inside a single file easier. For

this case, Pylint supports regular expression with several named

capturing group.

Rather than emitting name warnings immediately, Pylint will determine

the prevalent naming style inside each module and enforce it on all

names.

Consider the following (simplified) example:

pylint --function-rgx='(?:(?P<snake>[a-z_]+)|(?P<camel>_?[A-Z]+))$' sample.py

The regular expression defines two naming styles, "snake" for snake-

case names, and "camel" for camel-case names.

In "sample.py", the function name on line 1 and 7 will mark the module

and enforce the match of named group "snake" for the remaining names

in the module:

def valid_snake_case(arg):

...

def InvalidCamelCase(arg):

...

def more_valid_snake_case(arg):

...

Because of this, the name on line 4 will trigger an "invalid-name"

warning, even though the name matches the given regex.

Matches named "exempt" or "ignore" can be used for non-tainting names,

to prevent built-in or interface-dictated names to trigger certain

naming styles.

--name-group=<name1:name2:...,...>

Default value: empty

Format: comma-separated groups of colon-separated names.

This option can be used to combine name styles. For example,

"function:method" enforces that functions and methods use the same

style, and a style triggered by either name type carries over to

the other. This requires that the regular expression for the

combined name types use the same group names.

Name Hints

----------

--include-naming-hint=y|n

Default: off

Include a hint for the correct name format with every "invalid-

name" warning.

Name hints default to the regular expression, but can be separately

configured with the "--<name-type>-hint" options.