Developers may define a list named __all__ in a module to limit the names imported from it by wildcard imports (from mymodule
import *). This list can only reference defined names, otherwise an AttributeError will be raised when the module is imported.
from mymodule import my_func __all__ = ["unknown_func"] # Noncompliant. "unknown_func" is undefined
from mymodule import my_func __all__ = ["my_func"]