[Python-checkins] python/dist/src/Lib decimal.py,1.31.2.2,1.31.2.3

[rhettinger at users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv16884/Lib

Modified Files:
      Tag: release24-maint
	decimal.py 
Log Message:
- Fixed decimal operator and comparison methods to return NotImplemented
  instead of raising a TypeError when interacting with other types. 
  Allows other classes to successfully implement __radd__ style methods.



Index: decimal.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/decimal.py,v
retrieving revision 1.31.2.2
retrieving revision 1.31.2.3
diff -u -d -r1.31.2.2 -r1.31.2.3
--- decimal.py	15 Mar 2005 23:36:19 -0000	1.31.2.2
+++ decimal.py	27 Mar 2005 10:55:26 -0000	1.31.2.3
@@ -645,6 +645,8 @@
 
     def __cmp__(self, other, context=None):
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if self._is_special or other._is_special:
             ans = self._check_nans(other, context)
@@ -696,12 +698,12 @@
 
     def __eq__(self, other):
         if not isinstance(other, (Decimal, int, long)):
-            return False
+            return NotImplemented
         return self.__cmp__(other) == 0
 
     def __ne__(self, other):
         if not isinstance(other, (Decimal, int, long)):
-            return True
+            return NotImplemented
         return self.__cmp__(other) != 0
 
     def compare(self, other, context=None):
@@ -714,6 +716,8 @@
         Like __cmp__, but returns Decimal instances.
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         #compare(NaN, NaN) = NaN
         if (self._is_special or other and other._is_special):
@@ -919,6 +923,8 @@
         -INF + INF (or the reverse) cause InvalidOperation errors.
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if context is None:
             context = getcontext()
@@ -1006,6 +1012,8 @@
     def __sub__(self, other, context=None):
         """Return self + (-other)"""
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if self._is_special or other._is_special:
             ans = self._check_nans(other, context=context)
@@ -1023,6 +1031,8 @@
     def __rsub__(self, other, context=None):
         """Return other + (-self)"""
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         tmp = Decimal(self)
         tmp._sign = 1 - tmp._sign
@@ -1068,6 +1078,8 @@
         (+-) INF * 0 (or its reverse) raise InvalidOperation.
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if context is None:
             context = getcontext()
@@ -1140,6 +1152,10 @@
         computing the other value are not raised.
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            if divmod in (0, 1):
+                return NotImplemented
+            return (NotImplemented, NotImplemented)
 
         if context is None:
             context = getcontext()
@@ -1292,6 +1308,8 @@
     def __rdiv__(self, other, context=None):
         """Swaps self/other and returns __div__."""
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
         return other.__div__(self, context=context)
     __rtruediv__ = __rdiv__
 
@@ -1304,6 +1322,8 @@
     def __rdivmod__(self, other, context=None):
         """Swaps self/other and returns __divmod__."""
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
         return other.__divmod__(self, context=context)
 
     def __mod__(self, other, context=None):
@@ -1311,6 +1331,8 @@
         self % other
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if self._is_special or other._is_special:
             ans = self._check_nans(other, context)
@@ -1325,6 +1347,8 @@
     def __rmod__(self, other, context=None):
         """Swaps self/other and returns __mod__."""
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
         return other.__mod__(self, context=context)
 
     def remainder_near(self, other, context=None):
@@ -1332,6 +1356,8 @@
         Remainder nearest to 0-  abs(remainder-near) <= other/2
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if self._is_special or other._is_special:
             ans = self._check_nans(other, context)
@@ -1411,6 +1437,8 @@
     def __rfloordiv__(self, other, context=None):
         """Swaps self/other and returns __floordiv__."""
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
         return other.__floordiv__(self, context=context)
 
     def __float__(self):
@@ -1661,6 +1689,8 @@
         If modulo is None (default), don't take it mod modulo.
         """
         n = _convert_other(n)
+        if n is NotImplemented:
+            return n
 
         if context is None:
             context = getcontext()
@@ -1747,6 +1777,8 @@
     def __rpow__(self, other, context=None):
         """Swaps self/other and returns __pow__."""
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
         return other.__pow__(self, context=context)
 
     def normalize(self, context=None):
@@ -2001,6 +2033,8 @@
         NaN (and signals if one is sNaN).  Also rounds.
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if self._is_special or other._is_special:
             # if one operand is a quiet NaN and the other is number, then the
@@ -2048,6 +2082,8 @@
         NaN (and signals if one is sNaN).  Also rounds.
         """
         other = _convert_other(other)
+        if other is NotImplemented:
+            return other
 
         if self._is_special or other._is_special:
             # if one operand is a quiet NaN and the other is number, then the
@@ -2874,8 +2910,7 @@
         return other
     if isinstance(other, (int, long)):
         return Decimal(other)
-
-    raise TypeError, "You can interact Decimal only with int, long or Decimal data types."
+    return NotImplemented
 
 _infinity_map = {
     'inf' : 1,