rspec/rules/S1722/python/rule.adoc

== Why is this an issue?

The new style of class creation, with the declaration of a parent class, created a unified object model in Python, so that the type of an instantiated class is equal to its class. In Python 2.2-2.7, this is not the case for old-style classes. In Python 3+ all classes are new-style classes. However, since the behavior can differ from 2.2+ to 3+, explicitly inheriting from ``++object++`` (if there is no better candidate) is recommended.


=== Noncompliant code example

[source,python]
----
class MyClass():
    pass
----


=== Compliant solution

[source,python]
----
class MyClass(object):
    pass
----



ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Add inheritance from "object" or some other new-style class.


'''
== Comments And Links
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=== on 15 May 2014, 13:55:35 Pierre-Yves Nicolas wrote:
In Python 2.x, a class is an old-style class if it does not subclass a new-style class. If a class subclasses another class, we should check recursively whether the superclass is a new-style class. If a class does not subclass any class, we know for sure that it is an old-style class.


See \https://docs.python.org/2/whatsnew/2.2.html#old-and-new-classes

endif::env-github,rspecator-view[]