[Python-checkins] r60785 - in python/trunk/Lib: fractions.py test/test_fractions.py

Thu Feb 14 07:12:24 CET 2008

Author: jeffrey.yasskin
Date: Thu Feb 14 07:12:24 2008
New Revision: 60785
Modified:
 python/trunk/Lib/fractions.py
 python/trunk/Lib/test/test_fractions.py
Log:
Performance optimizations on Fraction's constructor.
 ./python.exe -m timeit -s 'from fractions import Fraction' 'Fraction(3)`
31.7 usec/loop -> 9.2 usec/loop
 ./python.exe -m timeit -s 'from fractions import Fraction' 'Fraction(3, 2)'`
27.7 usec/loop -> 9.32 usec/loop
 ./python.exe -m timeit -s 'from fractions import Fraction; f = Fraction(3, 2)' 'Fraction(f)'
31.9 usec/loop -> 14.3 usec/loop
Modified: python/trunk/Lib/fractions.py
==============================================================================

--- python/trunk/Lib/fractions.py	(original)
+++ python/trunk/Lib/fractions.py	Thu Feb 14 07:12:24 2008
@@ -64,7 +64,7 @@
 """
 self = super(Fraction, cls).__new__(cls)
 
- if denominator == 1:
+ if type(numerator) not in (int, long) and denominator == 1:
 if isinstance(numerator, basestring):
 # Handle construction from strings.
 input = numerator
@@ -86,24 +86,22 @@
 if m.group('sign') == '-':
 numerator = -numerator
 
- elif (not isinstance(numerator, numbers.Integral) and
- isinstance(numerator, Rational)):
- # Handle copies from other rationals.
+ elif isinstance(numerator, Rational):
+ # Handle copies from other rationals. Integrals get
+ # caught here too, but it doesn't matter because
+ # denominator is already 1.
 other_rational = numerator
 numerator = other_rational.numerator
 denominator = other_rational.denominator
 
- if (not isinstance(numerator, numbers.Integral) or
- not isinstance(denominator, numbers.Integral)):
- raise TypeError("Fraction(%(numerator)s, %(denominator)s):"
- " Both arguments must be integral." % locals())
-
 if denominator == 0:
 raise ZeroDivisionError('Fraction(%s, 0)' % numerator)
 
+ numerator = numerator.__index__()
+ denominator = denominator.__index__()
 g = gcd(numerator, denominator)
- self._numerator = int(numerator // g)
- self._denominator = int(denominator // g)
+ self._numerator = numerator // g
+ self._denominator = denominator // g
 return self
 
 @classmethod
Modified: python/trunk/Lib/test/test_fractions.py
==============================================================================
--- python/trunk/Lib/test/test_fractions.py	(original)
+++ python/trunk/Lib/test/test_fractions.py	Thu Feb 14 07:12:24 2008
@@ -62,11 +62,11 @@
 
 self.assertRaisesMessage(ZeroDivisionError, "Fraction(12, 0)",
 F, 12, 0)
- self.assertRaises(TypeError, F, 1.5)
- self.assertRaises(TypeError, F, 1.5 + 3j)
+ self.assertRaises(AttributeError, F, 1.5)
+ self.assertRaises(AttributeError, F, 1.5 + 3j)
 
- self.assertRaises(TypeError, F, F(1, 2), 3)
- self.assertRaises(TypeError, F, "3/2", 3)
+ self.assertRaises(AttributeError, F, F(1, 2), 3)
+ self.assertRaises(AttributeError, F, "3/2", 3)
 
 def testFromString(self):
 self.assertEquals((5, 1), _components(F("5")))
