diff options
| -rw-r--r-- | Doc/lib/libstdtypes.tex | 10 | ||||
| -rw-r--r-- | Lib/UserDict.py | 16 | ||||
| -rw-r--r-- | Lib/test/test_types.py | 6 | ||||
| -rw-r--r-- | Lib/test/test_userdict.py | 6 | ||||
| -rw-r--r-- | Misc/NEWS | 6 | ||||
| -rw-r--r-- | Objects/dictobject.c | 18 |
6 files changed, 51 insertions, 11 deletions
diff --git a/Doc/lib/libstdtypes.tex b/Doc/lib/libstdtypes.tex index 0006c76..1a7b505 100644 --- a/Doc/lib/libstdtypes.tex +++ b/Doc/lib/libstdtypes.tex @@ -1104,9 +1104,10 @@ arbitrary objects): {\code{\var{a}[\var{k}]} if \code{\var{k} in \var{a}}, else \var{x} (also setting it)} {(5)} - \lineiii{\var{a}.pop(\var{k})} - {remove specified \var{key} and return corresponding \var{value}} - {} + \lineiii{\var{a}.pop(\var{k}\optional{, \var{x}})} + {\code{\var{a}[\var{k}]} if \code{\var{k} in \var{a}}, + else \var{x} (and remove k)} + {(8)} \lineiii{\var{a}.popitem()} {remove and return an arbitrary (\var{key}, \var{value}) pair} {(6)} @@ -1155,6 +1156,9 @@ over a dictionary, as often used in set algorithms. \item[(7)] \function{fromkeys()} is a class method that returns a new dictionary. \var{value} defaults to \code{None}. \versionadded{2.3} + +\item[(8)] \function{pop()} raises a \exception{KeyError} when no default +value is given and the key is not found. \versionadded{2.3} \end{description} diff --git a/Lib/UserDict.py b/Lib/UserDict.py index fb9cdd5..6b5c9da 100644 --- a/Lib/UserDict.py +++ b/Lib/UserDict.py @@ -55,8 +55,8 @@ class UserDict: if not self.has_key(key): self[key] = failobj return self[key] - def pop(self, key): - return self.data.pop(key) + def pop(self, key, *args): + return self.data.pop(key, *args) def popitem(self): return self.data.popitem() def __contains__(self, key): @@ -117,8 +117,16 @@ class DictMixin: except KeyError: self[key] = default return default - def pop(self, key): - value = self[key] + def pop(self, key, *args): + if len(args) > 1: + raise TypeError, "pop expected at most 2 arguments, got "\ + + repr(1 + len(args)) + try: + value = self[key] + except KeyError: + if args: + return args[0] + raise del self[key] return value def popitem(self): diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py index d571a02..f2a7ccd 100644 --- a/Lib/test/test_types.py +++ b/Lib/test/test_types.py @@ -643,10 +643,14 @@ else: raise TestFailed, "{}.pop(k) doesn't raise KeyError when dictionary is emp # see SF bug #689659 x = 4503599627370496L y = 4503599627370496 -h = {x: 'anything', y: 'something else'} +h = {x: 'anything', y: 'something else'} if h[x] != h[y]: raise TestFailed, "long/int key should match" +if d.pop(k, v) != v: raise TestFailed, "{}.pop(k, v) doesn't return default value" +d[k] = v +if d.pop(k, 1) != v: raise TestFailed, "{}.pop(k, v) doesn't find known key/value pair" + d[1] = 1 try: for i in d: diff --git a/Lib/test/test_userdict.py b/Lib/test/test_userdict.py index d3e8002..cb98308 100644 --- a/Lib/test/test_userdict.py +++ b/Lib/test/test_userdict.py @@ -139,6 +139,9 @@ class UserDictTest(unittest.TestCase): t = UserDict.UserDict(x=42) self.assertEqual(t.pop("x"), 42) self.assertRaises(KeyError, t.pop, "x") + self.assertEqual(t.pop("x", 1), 1) + t["x"] = 42 + self.assertEqual(t.pop("x", 1), 42) # Test popitem t = UserDict.UserDict(x=42) @@ -242,6 +245,9 @@ class UserDictMixinTest(unittest.TestCase): self.assertEqual(s.pop(10), 'ten') self.assert_(10 not in s) s[10] = 'ten' + self.assertEqual(s.pop("x", 1), 1) + s["x"] = 42 + self.assertEqual(s.pop("x", 1), 42) # popitem k, v = s.popitem() @@ -12,6 +12,12 @@ What's New in Python 2.3 beta 1? Core and builtins ----------------- +- dict.pop now takes an optional argument specifying a default + value to return if the key is not in the dict. If a default is not + given and the key is not found, a KeyError will still be raised. + Parallel changes were made to UserDict.UserDict and UserDict.DictMixin. + [SF patch #693753] (contributed by Michael Stone.) + - sys.getfilesystemencoding() was added to expose Py_FileSystemDefaultEncoding. diff --git a/Objects/dictobject.c b/Objects/dictobject.c index f7f2d6b..633f2ce 100644 --- a/Objects/dictobject.c +++ b/Objects/dictobject.c @@ -1544,13 +1544,20 @@ dict_clear(register dictobject *mp) } static PyObject * -dict_pop(dictobject *mp, PyObject *key) +dict_pop(dictobject *mp, PyObject *args) { long hash; dictentry *ep; PyObject *old_value, *old_key; + PyObject *key, *deflt = NULL; + if(!PyArg_UnpackTuple(args, "pop", 1, 2, &key, &deflt)) + return NULL; if (mp->ma_used == 0) { + if (deflt) { + Py_INCREF(deflt); + return deflt; + } PyErr_SetString(PyExc_KeyError, "pop(): dictionary is empty"); return NULL; @@ -1563,6 +1570,10 @@ dict_pop(dictobject *mp, PyObject *key) } ep = (mp->ma_lookup)(mp, key, hash); if (ep->me_value == NULL) { + if (deflt) { + Py_INCREF(deflt); + return deflt; + } PyErr_SetObject(PyExc_KeyError, key); return NULL; } @@ -1719,7 +1730,8 @@ PyDoc_STRVAR(setdefault_doc__, "D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D"); PyDoc_STRVAR(pop__doc__, -"D.pop(k) -> v, remove specified key and return the corresponding value"); +"D.pop(k[,d]) -> v, remove specified key and return the corresponding value\n\ +If key is not found, d is returned if given, otherwise KeyError is raised"); PyDoc_STRVAR(popitem__doc__, "D.popitem() -> (k, v), remove and return some (key, value) pair as a\n\ @@ -1763,7 +1775,7 @@ static PyMethodDef mapp_methods[] = { get__doc__}, {"setdefault", (PyCFunction)dict_setdefault, METH_VARARGS, setdefault_doc__}, - {"pop", (PyCFunction)dict_pop, METH_O, + {"pop", (PyCFunction)dict_pop, METH_VARARGS, pop__doc__}, {"popitem", (PyCFunction)dict_popitem, METH_NOARGS, popitem__doc__}, |