Issue20467: clarify __init__'s role

This commit is contained in:
Ethan Furman 2015-01-14 21:57:15 -08:00
commit 9fdb0fe17b
1 changed files with 11 additions and 7 deletions

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@ -1100,13 +1100,17 @@ Basic customization
.. index:: pair: class; constructor
Called when the instance is created. The arguments are those passed to the
class constructor expression. If a base class has an :meth:`__init__` method,
the derived class's :meth:`__init__` method, if any, must explicitly call it to
ensure proper initialization of the base class part of the instance; for
example: ``BaseClass.__init__(self, [args...])``. As a special constraint on
constructors, no value may be returned; doing so will cause a :exc:`TypeError`
to be raised at runtime.
Called after the instance has been created (by :meth:`__new__`), but before
it is returned to the caller. The arguments are those passed to the
class constructor expression. If a base class has an :meth:`__init__`
method, the derived class's :meth:`__init__` method, if any, must explicitly
call it to ensure proper initialization of the base class part of the
instance; for example: ``BaseClass.__init__(self, [args...])``.
Because :meth:`__new__` and :meth:`__init__` work together in constructing
objects (:meth:`__new__` to create it, and :meth:`__init__` to customise it),
no non-``None`` value may be returned by :meth:`__init__`; doing so will
cause a :exc:`TypeError` to be raised at runtime.
.. method:: object.__del__(self)