15. types
— 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. It is safe to use from types import *
— the
module does not export any names besides the ones listed here. 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 *
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 int()
and
str()
are also names for the corresponding types. This is now the
preferred way to access the type instead of using the 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:
-
types.
NoneType
¶ The type of
None
.
-
types.
BooleanType
¶ The type of the
bool
valuesTrue
andFalse
; alias of the built-inbool
.New in version 2.3.
-
types.
ComplexType
¶ The type of complex numbers (e.g.
1.0j
). This is not defined if Python was built without complex number support.
-
types.
UnicodeType
¶ The type of Unicode character strings (e.g.
u'Spam'
). This is not defined if Python was built without Unicode support. It’s an alias of the built-inunicode
.
-
types.
DictionaryType
¶ An alternate name for
DictType
.
-
types.
FunctionType
¶ -
types.
LambdaType
¶ The type of user-defined functions and functions created by
lambda
expressions.
-
types.
GeneratorType
¶ The type of generator-iterator objects, produced by calling a generator function.
New in version 2.2.
-
types.
ClassType
¶ The type of user-defined old-style classes.
-
types.
InstanceType
¶ The type of instances of user-defined old-style classes.
-
types.
MethodType
¶ The type of methods of user-defined class instances.
-
types.
UnboundMethodType
¶ An alternate name for
MethodType
.
-
types.
BuiltinFunctionType
¶ -
types.
BuiltinMethodType
¶ The type of built-in functions like
len()
orsys.exit()
, and methods of built-in classes. (Here, the term “built-in” means “written in C”.)
-
types.
ModuleType
¶ The type of modules.
-
types.
EllipsisType
¶ The type of
Ellipsis
.
-
types.
TracebackType
¶ The type of traceback objects such as found in
sys.exc_traceback
.
-
types.
FrameType
¶ The type of frame objects such as found in
tb.tb_frame
iftb
is a traceback object.
-
types.
DictProxyType
¶ The type of dict proxies, such as
TypeType.__dict__
.
-
types.
NotImplementedType
¶ The type of
NotImplemented
-
types.
GetSetDescriptorType
¶ The type of objects defined in extension modules with
PyGetSetDef
, such asFrameType.f_locals
orarray.array.typecode
. This type is used as descriptor for object attributes; it has the same purpose as theproperty
type, but for classes defined in extension modules.New in version 2.5.
-
types.
MemberDescriptorType
¶ The type of objects defined in extension modules with
PyMemberDef
, such asdatetime.timedelta.days
. This type is used as descriptor for simple C data members which use standard conversion functions; it has the same purpose as theproperty
type, but for classes defined in extension modules.New in version 2.5.
-
types.
StringTypes
¶ A sequence containing
StringType
andUnicodeType
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 containsUnicodeType
if it has been built in the running version of Python. For example:isinstance(s, types.StringTypes)
.New in version 2.2.