cpython/Lib/types.py
Barry Warsaw 00decd7835 Patch #1520294: Support for getset and member descriptors in types.py,
inspect.py, and pydoc.py.  Specifically, this allows for querying the type of
an object against these built-in C types and more importantly, for getting
their docstrings printed in the interactive interpreter's help() function.

This patch includes a new built-in module called _types which provides
definitions of getset and member descriptors for use by the types.py module.
These types are exposed as types.GetSetDescriptorType and
types.MemberDescriptorType.  Query functions are provided as
inspect.isgetsetdescriptor() and inspect.ismemberdescriptor().  The
implementations of these are robust enough to work with Python implementations
other than CPython, which may not have these fundamental types.

The patch also includes documentation and test suite updates.

I commit these changes now under these guiding principles:

1. Silence is assent.  The release manager has not said "no", and of the few
   people that cared enough to respond to the thread, the worst vote was "0".

2. It's easier to ask for forgiveness than permission.

3. It's so dang easy to revert stuff in svn, that you could view this as a
   forcing function. :)

Windows build patches will follow.
2006-07-27 23:43:15 +00:00

101 lines
2.5 KiB
Python

"""Define names for all type symbols known in the standard interpreter.
Types that are part of optional modules (e.g. array) are not listed.
"""
import sys
# Iterators in Python aren't a matter of type but of protocol. A large
# and changing number of builtin types implement *some* flavor of
# iterator. Don't check the type! Use hasattr to check for both
# "__iter__" and "next" attributes instead.
NoneType = type(None)
TypeType = type
ObjectType = object
IntType = int
LongType = long
FloatType = float
BooleanType = bool
try:
ComplexType = complex
except NameError:
pass
StringType = str
# StringTypes is already outdated. Instead of writing "type(x) in
# types.StringTypes", you should use "isinstance(x, basestring)". But
# we keep around for compatibility with Python 2.2.
try:
UnicodeType = unicode
StringTypes = (StringType, UnicodeType)
except NameError:
StringTypes = (StringType,)
BufferType = buffer
TupleType = tuple
ListType = list
DictType = DictionaryType = dict
def _f(): pass
FunctionType = type(_f)
LambdaType = type(lambda: None) # Same as FunctionType
try:
CodeType = type(_f.func_code)
except RuntimeError:
# Execution in restricted environment
pass
def _g():
yield 1
GeneratorType = type(_g())
class _C:
def _m(self): pass
ClassType = type(_C)
UnboundMethodType = type(_C._m) # Same as MethodType
_x = _C()
InstanceType = type(_x)
MethodType = type(_x._m)
BuiltinFunctionType = type(len)
BuiltinMethodType = type([].append) # Same as BuiltinFunctionType
ModuleType = type(sys)
FileType = file
XRangeType = xrange
try:
raise TypeError
except TypeError:
try:
tb = sys.exc_info()[2]
TracebackType = type(tb)
FrameType = type(tb.tb_frame)
except AttributeError:
# In the restricted environment, exc_info returns (None, None,
# None) Then, tb.tb_frame gives an attribute error
pass
tb = None; del tb
SliceType = slice
EllipsisType = type(Ellipsis)
DictProxyType = type(TypeType.__dict__)
NotImplementedType = type(NotImplemented)
# Extension types defined in a C helper module. XXX There may be no
# equivalent in implementations other than CPython, so it seems better to
# leave them undefined then to set them to e.g. None.
try:
import _types
except ImportError:
pass
else:
GetSetDescriptorType = type(_types.Helper.getter)
MemberDescriptorType = type(_types.Helper.member)
del _types
del sys, _f, _g, _C, _x # Not for export