[Python-checkins] r42916 - in python/trunk: Doc/lib/libfuncs.tex Lib/test/test_descr.py Misc/NEWS Objects/descrobject.c

Wed Mar 8 19:09:29 CET 2006

Author: georg.brandl
Date: Wed Mar 8 19:09:27 2006
New Revision: 42916
Modified:
 python/trunk/Doc/lib/libfuncs.tex
 python/trunk/Lib/test/test_descr.py
 python/trunk/Misc/NEWS
 python/trunk/Objects/descrobject.c
Log:
Patch #1434038: property() now uses the getter's docstring if there is
no "doc" argument given. This makes it possible to legitimately use
property() as a decorator to produce a read-only property.
Modified: python/trunk/Doc/lib/libfuncs.tex
==============================================================================

--- python/trunk/Doc/lib/libfuncs.tex	(original)
+++ python/trunk/Doc/lib/libfuncs.tex	Wed Mar 8 19:09:27 2006
@@ -771,7 +771,12 @@
 x = property(getx, setx, delx, "I'm the 'x' property.")
 \end{verbatim}
 
+ If given, \var{doc} will be the docstring of the property attribute.
+ Otherwise, the property will copy \var{fget}'s docstring (if it
+ exists).
+
 \versionadded{2.2}
+ \versionchanged[Use \var{fget}'s docstring if no \var{doc} given]{2.5}
 \end{funcdesc}
 
 \begin{funcdesc}{range}{\optional{start,} stop\optional{, step}}
Modified: python/trunk/Lib/test/test_descr.py
==============================================================================
--- python/trunk/Lib/test/test_descr.py	(original)
+++ python/trunk/Lib/test/test_descr.py	Wed Mar 8 19:09:27 2006
@@ -2008,6 +2008,18 @@
 else:
 raise TestFailed, "expected ZeroDivisionError from bad property"
 
+ class E(object):
+ def getter(self):
+ "getter method"
+ return 0
+ def setter(self, value):
+ "setter method"
+ pass
+ prop = property(getter)
+ vereq(prop.__doc__, "getter method")
+ prop2 = property(fset=setter)
+ vereq(prop2.__doc__, None)
+
 def supers():
 if verbose: print "Testing super..."
 
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Wed Mar 8 19:09:27 2006
@@ -12,6 +12,10 @@
 Core and builtins
 -----------------
 
+- Patch #1434038: property() now uses the getter's docstring if there is
+ no "doc" argument given. This makes it possible to legitimately use
+ property() as a decorator to produce a read-only property.
+
 - PEP 357, patch 1436368: add an __index__ method to int/long and a matching
 nb_index slot to the PyNumberMethods struct. The slot is consulted instead
 of requiring an int or long in slicing and a few other contexts, enabling
Modified: python/trunk/Objects/descrobject.c
==============================================================================
--- python/trunk/Objects/descrobject.c	(original)
+++ python/trunk/Objects/descrobject.c	Wed Mar 8 19:09:27 2006
@@ -1081,6 +1081,8 @@
 class property(object):
 
 def __init__(self, fget=None, fset=None, fdel=None, doc=None):
+ if doc is None and fget is not None and hasattr(fget, "__doc__"):
+ doc = fget.__doc__
 self.__get = fget
 self.__set = fset
 self.__del = fdel
@@ -1182,6 +1184,7 @@
 property_init(PyObject *self, PyObject *args, PyObject *kwds)
 {
 	PyObject *get = NULL, *set = NULL, *del = NULL, *doc = NULL;
+	PyObject *get_doc = NULL;
 	static char *kwlist[] = {"fget", "fset", "fdel", "doc", 0};
 	propertyobject *gs = (propertyobject *)self;
 
@@ -1196,6 +1199,15 @@
 	if (del == Py_None)
 		del = NULL;
 
+	/* if no docstring given and the getter has one, use that one */
+	if ((doc == NULL || doc == Py_None) && get != NULL && 
+	 PyObject_HasAttrString(get, "__doc__")) {
+		if (!(get_doc = PyObject_GetAttrString(get, "__doc__")))
+			return -1;
+		Py_DECREF(get_doc); /* it is INCREF'd again below */
+		doc = get_doc;
+	}
+
 	Py_XINCREF(get);
 	Py_XINCREF(set);
 	Py_XINCREF(del);
