.. index:: single: __len__() (mapping object method)
Called to implement truth value testing and the built-in operation
- ``bool()``; should return ``False`` or ``True``, or their integer equivalents
- ``0`` or ``1``. When this method is not defined, :meth:`__len__` is called,
- if it is defined, and the object is considered true if its result is nonzero.
- If a class defines neither :meth:`__len__` nor :meth:`__bool__`, all its
- instances are considered true.
+ ``bool()``; should return ``False`` or ``True``. When this method is not
+ defined, :meth:`__len__` is called, if it is defined, and the object is
+ considered true if its result is nonzero. If a class defines neither
+ :meth:`__len__` nor :meth:`__bool__`, all its instances are considered
+ true.
.. _attribute-access:
Core and Builtins
-----------------
+- Issue #6428: Since Python 3.0, the __bool__ method must return a bool
+ object, and not an int. Fix the corresponding error message, and the
+ documentation.
+
- The deprecated PyCObject has been removed.
- Issue #6347: Include inttypes.h as well as stdint.h in pyport.h.
}
else {
PyErr_Format(PyExc_TypeError,
- "%s should return "
- "bool or int, returned %s",
- (using_len ? "__len__"
- : "__bool__"),
+ "__bool__ should return "
+ "bool, returned %s",
Py_TYPE(temp)->tp_name);
result = -1;
}