Merged revisions 58211-58220 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r58211 | facundo.batista | 2007-09-19 19:53:25 +0200 (Wed, 19 Sep 2007) | 4 lines


  Issue #1772851.  Optimization of __hash__ to behave better for big big
  numbers.
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  r58216 | raymond.hettinger | 2007-09-20 05:03:43 +0200 (Thu, 20 Sep 2007) | 1 line

  Fit nits
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  r58217 | georg.brandl | 2007-09-20 10:44:59 +0200 (Thu, 20 Sep 2007) | 2 lines

  alternate -> alternative.
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  r58218 | georg.brandl | 2007-09-20 18:06:07 +0200 (Thu, 20 Sep 2007) | 2 lines

  Patch #1541463: optimize performance of cgi.FieldStorage operations.
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  r58219 | georg.brandl | 2007-09-20 18:45:27 +0200 (Thu, 20 Sep 2007) | 2 lines

  #1176: document that string methods don't take keyword args.
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  r58220 | thomas.wouters | 2007-09-20 19:35:10 +0200 (Thu, 20 Sep 2007) | 4 lines


  Try harder to stay within the 79-column limit. There's still two places that go (way) over, but those are harder to fix without suffering in readability.
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3 files changed, 48 insertions, 11 deletions

diff --git a/Lib/cgi.py b/Lib/cgi.py
index 7b457cc..cb92cfc 100755
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
@@ -604,23 +604,21 @@ class FieldStorage:
         """Dictionary style keys() method."""
         if self.list is None:
             raise TypeError("not indexable")
-        keys = []
-        for item in self.list:
-            if item.name not in keys: keys.append(item.name)
-        return keys
+        return list(set(item.name for item in self.list))
 
     def __contains__(self, key):
         """Dictionary style __contains__ method."""
         if self.list is None:
             raise TypeError("not indexable")
-        for item in self.list:
-            if item.name == key: return True
-        return False
+        return any(item.name == key for item in self.list)
 
     def __len__(self):
         """Dictionary style len(x) support."""
         return len(self.keys())
 
+    def __nonzero__(self):
+        return bool(self.list)
+
     def read_urlencoded(self):
         """Internal: read data in query string format."""
         qs = self.fp.read(self.length)
diff --git a/Lib/decimal.py b/Lib/decimal.py
index d7bd127..ffe6e9e 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -786,10 +786,17 @@ class Decimal(object):
             if self._isnan():
                 raise TypeError('Cannot hash a NaN value.')
             return hash(str(self))
-        i = int(self)
-        if self == Decimal(i):
-            return hash(i)
-        assert self.__bool__()   # '-0' handled by integer case
+        if not self:
+            return 0
+        if self._isinteger():
+            op = _WorkRep(self.to_integral_value())
+            # to make computation feasible for Decimals with large
+            # exponent, we use the fact that hash(n) == hash(m) for
+            # any two nonzero integers n and m such that (i) n and m
+            # have the same sign, and (ii) n is congruent to m modulo
+            # 2**64-1.  So we can replace hash((-1)**s*c*10**e) with
+            # hash((-1)**s*c*pow(10, e, 2**64-1).
+            return hash((-1)**op.sign*op.int*pow(10, op.exp, 2**64-1))
         return hash(str(self.normalize()))
 
     def as_tuple(self):
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 41d1dd5..513ba16 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -901,6 +901,38 @@ class DecimalUsabilityTest(unittest.TestCase):
     def test_hash_method(self):
         #just that it's hashable
         hash(Decimal(23))
+
+        test_values = [Decimal(sign*(2**m + n))
+                       for m in [0, 14, 15, 16, 17, 30, 31,
+                                 32, 33, 62, 63, 64, 65, 66]
+                       for n in range(-10, 10)
+                       for sign in [-1, 1]]
+        test_values.extend([
+                Decimal("-0"), # zeros
+                Decimal("0.00"),
+                Decimal("-0.000"),
+                Decimal("0E10"),
+                Decimal("-0E12"),
+                Decimal("10.0"), # negative exponent
+                Decimal("-23.00000"),
+                Decimal("1230E100"), # positive exponent
+                Decimal("-4.5678E50"),
+                # a value for which hash(n) != hash(n % (2**64-1))
+                # in Python pre-2.6
+                Decimal(2**64 + 2**32 - 1),
+                # selection of values which fail with the old (before
+                # version 2.6) long.__hash__
+                Decimal("1.634E100"),
+                Decimal("90.697E100"),
+                Decimal("188.83E100"),
+                Decimal("1652.9E100"),
+                Decimal("56531E100"),
+                ])
+
+        # check that hash(d) == hash(int(d)) for integral values
+        for value in test_values:
+            self.assertEqual(hash(value), hash(int(value)))
+
         #the same hash that to an int
         self.assertEqual(hash(Decimal(23)), hash(23))
         self.assertRaises(TypeError, hash, Decimal('NaN'))