cpython/Doc/library/types.rst

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:mod:`types` --- Names for built-in types
=========================================
.. module:: types
:synopsis: Names for built-in types.
This module defines names for some object types that are used by the standard
Python interpreter, but not for the types defined by various extension modules.
Also, it does not include some of the types that arise during processing such as
the ``listiterator`` type. New names exported by future versions of this module
will all end in ``Type``.
Typical use is for functions that do different things depending on their
argument types, like the following::
from types import IntType
def delete(mylist, item):
if type(item) is IntType:
del mylist[item]
else:
mylist.remove(item)
Starting in Python 2.2, built-in factory functions such as :func:`int` and
:func:`str` are also names for the corresponding types. This is now the
preferred way to access the type instead of using the :mod:`types` module.
Accordingly, the example above should be written as follows::
def delete(mylist, item):
if isinstance(item, int):
del mylist[item]
else:
mylist.remove(item)
The module defines the following names:
.. data:: NoneType
The type of ``None``.
.. data:: TypeType
.. index:: builtin: type
The type of type objects (such as returned by :func:`type`); alias of the
built-in :class:`type`.
.. data:: BooleanType
The type of the :class:`bool` values ``True`` and ``False``; alias of the
built-in :class:`bool`.
.. data:: IntType
The type of integers (e.g. ``1``); alias of the built-in :class:`int`.
.. data:: LongType
The type of long integers (e.g. ``1L``); alias of the built-in :class:`long`.
.. data:: FloatType
The type of floating point numbers (e.g. ``1.0``); alias of the built-in
:class:`float`.
.. data:: ComplexType
The type of complex numbers (e.g. ``1.0j``). This is not defined if Python was
built without complex number support.
.. data:: StringType
The type of character strings (e.g. ``'Spam'``); alias of the built-in
:class:`str`.
.. data:: TupleType
The type of tuples (e.g. ``(1, 2, 3, 'Spam')``); alias of the built-in
:class:`tuple`.
.. data:: ListType
The type of lists (e.g. ``[0, 1, 2, 3]``); alias of the built-in
:class:`list`.
.. data:: DictType
The type of dictionaries (e.g. ``{'Bacon': 1, 'Ham': 0}``); alias of the
built-in :class:`dict`.
.. data:: DictionaryType
An alternate name for ``DictType``.
.. data:: FunctionType
The type of user-defined functions and lambdas.
.. data:: LambdaType
An alternate name for ``FunctionType``.
.. data:: GeneratorType
The type of generator-iterator objects, produced by calling a generator
function.
.. data:: CodeType
.. index:: builtin: compile
The type for code objects such as returned by :func:`compile`.
.. data:: ClassType
The type of user-defined classes.
.. data:: MethodType
The type of methods of user-defined class instances.
.. data:: UnboundMethodType
An alternate name for ``MethodType``.
.. data:: BuiltinFunctionType
The type of built-in functions like :func:`len` or :func:`sys.exit`.
.. data:: BuiltinMethodType
An alternate name for ``BuiltinFunction``.
.. data:: ModuleType
The type of modules.
.. data:: FileType
The type of open file objects such as ``sys.stdout``; alias of the built-in
:class:`file`.
.. data:: RangeType
.. index:: builtin: range
The type of range objects returned by :func:`range`; alias of the built-in
:class:`range`.
.. data:: SliceType
.. index:: builtin: slice
The type of objects returned by :func:`slice`; alias of the built-in
:class:`slice`.
.. data:: EllipsisType
The type of ``Ellipsis``.
.. data:: TracebackType
The type of traceback objects such as found in ``sys.exc_info()[2]``.
.. data:: FrameType
The type of frame objects such as found in ``tb.tb_frame`` if ``tb`` is a
traceback object.
.. data:: BufferType
.. index:: builtin: buffer
The type of buffer objects created by the :func:`buffer` function.
.. data:: DictProxyType
The type of dict proxies, such as ``TypeType.__dict__``.
.. data:: NotImplementedType
The type of ``NotImplemented``
.. data:: GetSetDescriptorType
The type of objects defined in extension modules with ``PyGetSetDef``, such as
``FrameType.f_locals`` or ``array.array.typecode``. This constant is not
defined in implementations of Python that do not have such extension types, so
for portable code use ``hasattr(types, 'GetSetDescriptorType')``.
.. data:: MemberDescriptorType
The type of objects defined in extension modules with ``PyMemberDef``, such as
``datetime.timedelta.days``. This constant is not defined in implementations of
Python that do not have such extension types, so for portable code use
``hasattr(types, 'MemberDescriptorType')``.
.. data:: StringTypes
A sequence containing ``StringType`` and ``UnicodeType`` used to facilitate
easier checking for any string object. Using this is more portable than using a
sequence of the two string types constructed elsewhere since it only contains
``UnicodeType`` if it has been built in the running version of Python. For
example: ``isinstance(s, types.StringTypes)``.