New submission from Géry <gery.o...@gmail.com>: ## Expected outcome
``` >>> hasattr(complex(), '__complex__') True >>> hasattr(float(), '__complex__') True >>> hasattr(int(), '__complex__') True ``` ## Actual outcome ``` >>> hasattr(complex(), '__complex__') False >>> hasattr(float(), '__complex__') False >>> hasattr(int(), '__complex__') False ``` ## Rationale The `numbers.Complex` abstract base class has a `__complex__` abstract method and the `numbers.Real` and `numbers.Integral` abstract base classes inherit from `numbers.Complex` (https://github.com/python/cpython/blob/v3.10.3/Lib/numbers.py#L45-L47): ``` @abstractmethod def __complex__(self): """Return a builtin complex instance. Called for complex(self).""" ``` The `complex` built-in type is a virtual subclass (nominal subtype) of `numbers.Complex` (https://github.com/python/cpython/blob/v3.10.3/Lib/numbers.py#L144): ``` Complex.register(complex) ``` The `float` built-in type is a virtual subclass (nominal subtype) of `numbers.Real` (https://github.com/python/cpython/blob/v3.10.3/Lib/numbers.py#L264): ``` Real.register(float) ``` The `int` built-in type is a virtual subclass (nominal subtype) of `numbers.Integral` (https://github.com/python/cpython/blob/v3.10.3/Lib/numbers.py#L393): ``` Integral.register(int) ``` `__complex__` is the only method of the abstract base classes of `numbers` missing from `complex`, `float`, and `int`: ``` >>> import numbers >>> for attr in dir(numbers.Complex): ... if not hasattr(complex(), attr): print(attr) ... __abstractmethods__ __complex__ __module__ __slots__ _abc_impl >>> for attr in dir(numbers.Real): ... if not hasattr(float(), attr): print(attr) ... __abstractmethods__ __complex__ __module__ __slots__ _abc_impl >>> for attr in dir(numbers.Integral): ... if not hasattr(int(), attr): print(attr) ... __abstractmethods__ __complex__ __module__ __slots__ _abc_impl ``` ---------- components: Interpreter Core messages: 415689 nosy: maggyero priority: normal severity: normal status: open title: The __complex__ method is missing from the complex, float, and int built-in types type: behavior versions: Python 3.10, Python 3.11, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue47083> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
