peps/pep-0294.txt at main · python/peps

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	PEP: 294
	Title: Type Names in the types Module
	Author: Oren Tirosh <oren at hishome.net>
	Status: Rejected
	Type: Standards Track
	Content-Type: text/x-rst
	Created: 19-Jun-2002
	Python-Version: 2.5
	Post-History:



	Abstract
	========

	This PEP proposes that symbols matching the type name should be added
	to the types module for all basic Python types in the types module::

	types.IntegerType -> types.int
	types.FunctionType -> types.function
	types.TracebackType -> types.traceback
	...

	The long capitalized names currently in the types module will be
	deprecated.

	With this change the types module can serve as a replacement for the
	new module. The new module shall be deprecated and listed in :pep:`4`.


	Pronouncement
	=============

	A centralized repository of type names was a mistake. Neither the
	"types" nor "new" modules should be carried forward to Python 3.0.

	In the meantime, it does not make sense to make the proposed updates
	to the modules. This would cause disruption without any compensating
	benefit.

	Instead, the problem that some internal types (frames, functions,
	etc.) don't live anywhere outside those modules may be addressed by
	either adding them to ``__builtin__`` or sys. This will provide a
	smoother transition to Python 3.0.


	Rationale
	=========

	Using two sets of names for the same objects is redundant and
	confusing.

	In Python versions prior to 2.2 the symbols matching many type names
	were taken by the factory functions for those types. Now all basic
	types have been unified with their factory functions and therefore the
	type names are available to be consistently used to refer to the type
	object.

	Most types are accessible as either builtins or in the new module but
	some types such as traceback and generator are only accessible through
	the types module under names which do not match the type name. This
	PEP provides a uniform way to access all basic types under a single
	set of names.


	Specification
	=============

	The types module shall pass the following test::

	import types
	for t in vars(types).values():
	if type(t) is type:
	assert getattr(types, t.__name__) is t

	The types 'class', 'instance method' and 'dict-proxy' have already
	been renamed to the valid Python identifiers 'classobj',
	'instancemethod' and 'dictproxy', making this possible.


	Backward compatibility
	======================

	Because of their widespread use it is not planned to actually remove
	the long names from the types module in some future version. However,
	the long names should be changed in documentation and library sources
	to discourage their use in new code.


	Reference Implementation
	========================

	A reference implementation is available in
	`issue #569328 <https://bugs.python.org/issue569328>`_.


	Copyright
	=========

	This document has been placed in the public domain.