mirror of https://github.com/python/cpython
Backport from Py3k branch:
Patch #1591665: implement the __dir__() special function lookup in PyObject_Dir. Had to change a few bits of the patch because classobjs and __methods__ are still in Py2.6.
This commit is contained in:
Georg Brandl
parent
2681beb23e
commit
871f1bc601
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@ -274,21 +274,34 @@ class C:
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\end{funcdesc}
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\begin{funcdesc}{dir}{\optional{object}}
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Without arguments, return the list of names in the current local
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symbol table. With an argument, attempts to return a list of valid
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attributes for that object. This information is gleaned from the
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object's \member{__dict__} attribute, if defined, and from the class
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or type object. The list is not necessarily complete.
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If the object is a module object, the list contains the names of the
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Without arguments, return the list of names in the current local scope. With
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an argument, attempt to return a list of valid attributes for that object.
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If the object has a method named \method{__dir__()}, this method will be
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called and must return the list of attributes. This allows objects that
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implement a custom \function{__getattr__()} or \function{__getattribute__()}
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function to customize the way \function{dir()} reports their attributes.
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If the object does not provide \method{__dir__()}, the function tries its best
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to gather information from the object's \member{__dict__} attribute, if
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defined, and from its type object. The resulting list is not necessarily
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complete, and may be inaccurate when the object has a custom
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\function{__getattr__()}.
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The default \function{dir()} mechanism behaves differently with different
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types of objects, as it attempts to produce the most relevant, rather than
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complete, information:
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\begin{itemize}
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\item If the object is a module object, the list contains the names of the
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module's attributes.
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If the object is a type or class object,
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the list contains the names of its attributes,
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and recursively of the attributes of its bases.
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Otherwise, the list contains the object's attributes' names,
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the names of its class's attributes,
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and recursively of the attributes of its class's base classes.
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The resulting list is sorted alphabetically.
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For example:
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\item If the object is a type or class object, the list contains the names of
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its attributes, and recursively of the attributes of its bases.
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\item Otherwise, the list contains the object's attributes' names, the names
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of its class's attributes, and recursively of the attributes of its class's
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base classes.
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\end{itemize}
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The resulting list is sorted alphabetically. For example:
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\begin{verbatim}
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>>> import struct
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@ -296,13 +309,19 @@ class C:
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['__builtins__', '__doc__', '__name__', 'struct']
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>>> dir(struct)
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['__doc__', '__name__', 'calcsize', 'error', 'pack', 'unpack']
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>>> class Foo(object):
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... def __dir__(self):
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... return ["kan", "ga", "roo"]
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...
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>>> f = Foo()
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>>> dir(f)
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['ga', 'kan', 'roo']
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\end{verbatim}
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\note{Because \function{dir()} is supplied primarily as a convenience
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for use at an interactive prompt,
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it tries to supply an interesting set of names more than it tries to
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supply a rigorously or consistently defined set of names,
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and its detailed behavior may change across releases.}
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\note{Because \function{dir()} is supplied primarily as a convenience for use
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at an interactive prompt, it tries to supply an interesting set of names
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more than it tries to supply a rigorously or consistently defined set of
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names, and its detailed behavior may change across releases.}
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\end{funcdesc}
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\begin{funcdesc}{divmod}{a, b}
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@ -259,12 +259,67 @@ class BuiltinTest(unittest.TestCase):
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self.assertRaises(TypeError, delattr)
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def test_dir(self):
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x = 1
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self.assert_('x' in dir())
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import sys
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self.assert_('modules' in dir(sys))
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# dir(wrong number of arguments)
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self.assertRaises(TypeError, dir, 42, 42)
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# dir() - local scope
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local_var = 1
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self.assert_('local_var' in dir())
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# dir(module)
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import sys
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self.assert_('exit' in dir(sys))
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# dir(module_with_invalid__dict__)
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import types
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class Foo(types.ModuleType):
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__dict__ = 8
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f = Foo("foo")
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self.assertRaises(TypeError, dir, f)
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# dir(type)
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self.assert_("strip" in dir(str))
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self.assert_("__mro__" not in dir(str))
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# dir(obj)
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class Foo(object):
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def __init__(self):
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self.x = 7
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self.y = 8
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self.z = 9
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f = Foo()
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self.assert_("y" in dir(f))
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# dir(obj_no__dict__)
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class Foo(object):
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__slots__ = []
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f = Foo()
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self.assert_("__repr__" in dir(f))
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# dir(obj_no__class__with__dict__)
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# (an ugly trick to cause getattr(f, "__class__") to fail)
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class Foo(object):
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__slots__ = ["__class__", "__dict__"]
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def __init__(self):
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self.bar = "wow"
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f = Foo()
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self.assert_("__repr__" not in dir(f))
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self.assert_("bar" in dir(f))
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# dir(obj_using __dir__)
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class Foo(object):
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def __dir__(self):
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return ["kan", "ga", "roo"]
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f = Foo()
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self.assert_(dir(f) == ["ga", "kan", "roo"])
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# dir(obj__dir__not_list)
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class Foo(object):
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def __dir__(self):
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return 7
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f = Foo()
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self.assertRaises(TypeError, dir, f)
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def test_divmod(self):
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self.assertEqual(divmod(12, 7), (1, 5))
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self.assertEqual(divmod(-12, 7), (-2, 2))
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@ -12,6 +12,10 @@ What's New in Python 2.6 alpha 1?
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Core and builtins
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-----------------
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- The dir() function has been extended to call the __dir__() method on
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its argument, if it exists. If not, it will work like before. This allows
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customizing the output of dir() in the presence of a __getattr__().
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- Patch #1675981: remove unreachable code from ``type.__new__()`` method.
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- Patch #1491866: change the complex() constructor to allow parthensized
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235
Objects/object.c
235
Objects/object.c
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@ -1566,6 +1566,8 @@ PyCallable_Check(PyObject *x)
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}
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}
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/* ------------------------- PyObject_Dir() helpers ------------------------- */
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/* Helper for PyObject_Dir.
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Merge the __dict__ of aclass into dict, and recursively also all
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the __dict__s of aclass's base classes. The order of merging isn't
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@ -1662,121 +1664,192 @@ merge_list_attr(PyObject* dict, PyObject* obj, const char *attrname)
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return result;
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}
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/* Like __builtin__.dir(arg). See bltinmodule.c's builtin_dir for the
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docstring, which should be kept in synch with this implementation. */
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PyObject *
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PyObject_Dir(PyObject *arg)
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/* Helper for PyObject_Dir without arguments: returns the local scope. */
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static PyObject *
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_dir_locals()
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{
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/* Set exactly one of these non-NULL before the end. */
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PyObject *result = NULL; /* result list */
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PyObject *masterdict = NULL; /* result is masterdict.keys() */
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/* If NULL arg, return the locals. */
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if (arg == NULL) {
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PyObject *names;
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PyObject *locals = PyEval_GetLocals();
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if (locals == NULL)
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goto error;
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result = PyMapping_Keys(locals);
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if (result == NULL)
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goto error;
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if (locals == NULL) {
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PyErr_SetString(PyExc_SystemError, "frame does not exist");
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return NULL;
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}
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/* Elif this is some form of module, we only want its dict. */
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else if (PyModule_Check(arg)) {
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masterdict = PyObject_GetAttrString(arg, "__dict__");
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if (masterdict == NULL)
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goto error;
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if (!PyDict_Check(masterdict)) {
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PyErr_SetString(PyExc_TypeError,
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"module.__dict__ is not a dictionary");
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goto error;
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names = PyMapping_Keys(locals);
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if (!names)
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return NULL;
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if (!PyList_Check(names)) {
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PyErr_Format(PyExc_TypeError,
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"dir(): expected keys() of locals to be a list, "
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"not '%.200s'", names->ob_type->tp_name);
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Py_DECREF(names);
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return NULL;
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}
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/* the locals don't need to be DECREF'd */
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return names;
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}
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/* Elif some form of type or class, grab its dict and its bases.
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We deliberately don't suck up its __class__, as methods belonging
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to the metaclass would probably be more confusing than helpful. */
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else if (PyType_Check(arg) || PyClass_Check(arg)) {
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masterdict = PyDict_New();
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if (masterdict == NULL)
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goto error;
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if (merge_class_dict(masterdict, arg) < 0)
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goto error;
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/* Helper for PyObject_Dir of type objects: returns __dict__ and __bases__.
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We deliberately don't suck up its __class__, as methods belonging to the
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metaclass would probably be more confusing than helpful.
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*/
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static PyObject *
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_specialized_dir_type(PyObject *obj)
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{
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PyObject *result = NULL;
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PyObject *dict = PyDict_New();
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if (dict != NULL && merge_class_dict(dict, obj) == 0)
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result = PyDict_Keys(dict);
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Py_XDECREF(dict);
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return result;
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}
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/* Else look at its dict, and the attrs reachable from its class. */
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/* Helper for PyObject_Dir of module objects: returns the module's __dict__. */
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static PyObject *
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_specialized_dir_module(PyObject *obj)
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{
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PyObject *result = NULL;
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PyObject *dict = PyObject_GetAttrString(obj, "__dict__");
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if (dict != NULL) {
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if (PyDict_Check(dict))
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result = PyDict_Keys(dict);
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else {
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PyObject *itsclass;
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/* Create a dict to start with. CAUTION: Not everything
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responding to __dict__ returns a dict! */
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masterdict = PyObject_GetAttrString(arg, "__dict__");
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if (masterdict == NULL) {
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PyErr_Format(PyExc_TypeError,
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"%.200s.__dict__ is not a dictionary",
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PyModule_GetName(obj));
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}
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}
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Py_XDECREF(dict);
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return result;
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}
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/* Helper for PyObject_Dir of generic objects: returns __dict__, __class__,
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and recursively up the __class__.__bases__ chain.
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*/
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static PyObject *
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_generic_dir(PyObject *obj)
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{
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PyObject *result = NULL;
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PyObject *dict = NULL;
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PyObject *itsclass = NULL;
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/* Get __dict__ (which may or may not be a real dict...) */
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dict = PyObject_GetAttrString(obj, "__dict__");
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if (dict == NULL) {
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PyErr_Clear();
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masterdict = PyDict_New();
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dict = PyDict_New();
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}
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else if (!PyDict_Check(masterdict)) {
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Py_DECREF(masterdict);
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masterdict = PyDict_New();
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else if (!PyDict_Check(dict)) {
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Py_DECREF(dict);
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dict = PyDict_New();
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}
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else {
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/* The object may have returned a reference to its
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dict, so copy it to avoid mutating it. */
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PyObject *temp = PyDict_Copy(masterdict);
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Py_DECREF(masterdict);
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masterdict = temp;
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/* Copy __dict__ to avoid mutating it. */
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PyObject *temp = PyDict_Copy(dict);
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Py_DECREF(dict);
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dict = temp;
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}
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if (masterdict == NULL)
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if (dict == NULL)
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goto error;
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/* Merge in __members__ and __methods__ (if any).
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XXX Would like this to go away someday; for now, it's
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XXX needed to get at im_self etc of method objects. */
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if (merge_list_attr(masterdict, arg, "__members__") < 0)
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* This is removed in Python 3000. */
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if (merge_list_attr(dict, obj, "__members__") < 0)
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goto error;
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if (merge_list_attr(masterdict, arg, "__methods__") < 0)
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if (merge_list_attr(dict, obj, "__methods__") < 0)
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goto error;
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/* Merge in attrs reachable from its class.
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CAUTION: Not all objects have a __class__ attr. */
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itsclass = PyObject_GetAttrString(arg, "__class__");
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/* Merge in attrs reachable from its class. */
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itsclass = PyObject_GetAttrString(obj, "__class__");
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if (itsclass == NULL)
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/* XXX(tomer): Perhaps fall back to obj->ob_type if no
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__class__ exists? */
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PyErr_Clear();
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else {
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int status = merge_class_dict(masterdict, itsclass);
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Py_DECREF(itsclass);
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if (status < 0)
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if (merge_class_dict(dict, itsclass) != 0)
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goto error;
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}
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result = PyDict_Keys(dict);
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/* fall through */
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error:
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Py_XDECREF(itsclass);
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Py_XDECREF(dict);
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return result;
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}
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assert((result == NULL) ^ (masterdict == NULL));
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if (masterdict != NULL) {
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/* The result comes from its keys. */
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assert(result == NULL);
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result = PyDict_Keys(masterdict);
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/* Helper for PyObject_Dir: object introspection.
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This calls one of the above specialized versions if no __dir__ method
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exists. */
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static PyObject *
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_dir_object(PyObject *obj)
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{
|
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PyObject * result = NULL;
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PyObject * dirfunc = PyObject_GetAttrString((PyObject*)obj->ob_type,
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"__dir__");
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assert(obj);
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if (dirfunc == NULL) {
|
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/* use default implementation */
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PyErr_Clear();
|
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if (PyModule_Check(obj))
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result = _specialized_dir_module(obj);
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else if (PyType_Check(obj) || PyClass_Check(obj))
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result = _specialized_dir_type(obj);
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else
|
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result = _generic_dir(obj);
|
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}
|
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else {
|
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/* use __dir__ */
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result = PyObject_CallFunctionObjArgs(dirfunc, obj, NULL);
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Py_DECREF(dirfunc);
|
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if (result == NULL)
|
||||
goto error;
|
||||
}
|
||||
return NULL;
|
||||
|
||||
assert(result);
|
||||
/* result must be a list */
|
||||
/* XXX(gbrandl): could also check if all items are strings */
|
||||
if (!PyList_Check(result)) {
|
||||
PyErr_Format(PyExc_TypeError,
|
||||
"Expected keys() to be a list, not '%.200s'",
|
||||
"__dir__() must return a list, not %.200s",
|
||||
result->ob_type->tp_name);
|
||||
goto error;
|
||||
}
|
||||
if (PyList_Sort(result) != 0)
|
||||
goto error;
|
||||
else
|
||||
goto normal_return;
|
||||
|
||||
error:
|
||||
Py_XDECREF(result);
|
||||
Py_DECREF(result);
|
||||
result = NULL;
|
||||
/* fall through */
|
||||
normal_return:
|
||||
Py_XDECREF(masterdict);
|
||||
}
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/* Implementation of dir() -- if obj is NULL, returns the names in the current
|
||||
(local) scope. Otherwise, performs introspection of the object: returns a
|
||||
sorted list of attribute names (supposedly) accessible from the object
|
||||
*/
|
||||
PyObject *
|
||||
PyObject_Dir(PyObject *obj)
|
||||
{
|
||||
PyObject * result;
|
||||
|
||||
if (obj == NULL)
|
||||
/* no object -- introspect the locals */
|
||||
result = _dir_locals();
|
||||
else
|
||||
/* object -- introspect the object */
|
||||
result = _dir_object(obj);
|
||||
|
||||
assert(result == NULL || PyList_Check(result));
|
||||
|
||||
if (result != NULL && PyList_Sort(result) != 0) {
|
||||
/* sorting the list failed */
|
||||
Py_DECREF(result);
|
||||
result = NULL;
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -495,15 +495,16 @@ builtin_dir(PyObject *self, PyObject *args)
|
|||
PyDoc_STRVAR(dir_doc,
|
||||
"dir([object]) -> list of strings\n"
|
||||
"\n"
|
||||
"Return an alphabetized list of names comprising (some of) the attributes\n"
|
||||
"of the given object, and of attributes reachable from it:\n"
|
||||
"\n"
|
||||
"No argument: the names in the current scope.\n"
|
||||
"Module object: the module attributes.\n"
|
||||
"Type or class object: its attributes, and recursively the attributes of\n"
|
||||
" its bases.\n"
|
||||
"Otherwise: its attributes, its class's attributes, and recursively the\n"
|
||||
" attributes of its class's base classes.");
|
||||
"If called without an argument, return the names in the current scope.\n"
|
||||
"Else, return an alphabetized list of names comprising (some of) the attributes\n"
|
||||
"of the given object, and of attributes reachable from it.\n"
|
||||
"If the object supplies a method named __dir__, it will be used; otherwise\n"
|
||||
"the default dir() logic is used and returns:\n"
|
||||
" for a module object: the module's attributes.\n"
|
||||
" for a class object: its attributes, and recursively the attributes\n"
|
||||
" of its bases.\n"
|
||||
" for an other object: its attributes, its class's attributes, and\n"
|
||||
" recursively the attributes of its class's base classes.");
|
||||
|
||||
static PyObject *
|
||||
builtin_divmod(PyObject *self, PyObject *args)
|
||||
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|
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Reference in New Issue