rspec/rules/S2823/python/rule.adoc

This rule raises an issue when the ``++__all__++`` property of a module contains objects that aren't strings.

== Why is this an issue?

The ``++__all__++`` property of a module is used to define the list of names that will be imported when performing a wildcard import of this module, i.e. when ``++from mymodule import *++`` is used.

In the following example:

[source,python]
----
# mymodule.py
def foo(): ...
def bar(): ...
__all__ = ["foo"]
----

Executing ``++from mymodule import *++`` from a different module will only import `foo`.

This list can only contain strings. If something other than a string is listed, a `TypeError` will be raised when trying to perform a wildcard import of the module.


To fix this issue, make sure that all properties listed in ``++__all__++`` are strings.

=== Code examples

==== Noncompliant code example

[source,python, diff-id=1,diff-type=noncompliant]
----
class MyClass:
    pass

__all__ = [
    MyClass  # Noncompliant: wildcard import will raise a TypeError
]
----


==== Compliant solution

[source,python,diff-id=1,diff-type=compliant]
----
class MyClass:
    pass

__all__ = [
    "MyClass"
]
----


== Resources

=== Documentation

* https://docs.python.org/3/tutorial/modules.html#importing-from-a-package[Python documentation  - Importing * From a Package]



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

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

=== Message

Replace this symbol with a string; "__all__" can only contain strings.


=== Highlighting

Primary: the wrong symbol in "__all__"


'''
== Comments And Links
(visible only on this page)

=== is related to: S5807

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