[Python-checkins] r60754 - python/trunk/Lib/fractions.py
mark.dickinson
python-checkins at python.org
Tue Feb 12 22:40:53 CET 2008
Author: mark.dickinson
Date: Tue Feb 12 22:40:53 2008
New Revision: 60754
Modified:
python/trunk/Lib/fractions.py
Log:
Revert change in r60712: turn alternate constructors back into
classmethods instead of staticmethods.
Modified: python/trunk/Lib/fractions.py
==============================================================================
--- python/trunk/Lib/fractions.py (original)
+++ python/trunk/Lib/fractions.py Tue Feb 12 22:40:53 2008
@@ -106,39 +106,39 @@
self._denominator = int(denominator // g)
return self
- @staticmethod
- def from_float(f):
+ @classmethod
+ def from_float(cls, f):
"""Converts a finite float to a rational number, exactly.
Beware that Fraction.from_float(0.3) != Fraction(3, 10).
"""
if not isinstance(f, float):
- raise TypeError("Fraction.from_float() only takes floats, "
- "not %r (%s)" % (f, type(f).__name__))
+ raise TypeError("%s.from_float() only takes floats, not %r (%s)" %
+ (cls.__name__, f, type(f).__name__))
if math.isnan(f) or math.isinf(f):
- raise TypeError("Cannot convert %r to Fraction." % f)
- return Fraction(*f.as_integer_ratio())
+ raise TypeError("Cannot convert %r to %s." % (f, cls.__name__))
+ return cls(*f.as_integer_ratio())
- @staticmethod
- def from_decimal(dec):
+ @classmethod
+ def from_decimal(cls, dec):
"""Converts a finite Decimal instance to a rational number, exactly."""
from decimal import Decimal
if not isinstance(dec, Decimal):
raise TypeError(
- "Fraction.from_decimal() only takes Decimals, not %r (%s)" %
- (dec, type(dec).__name__))
+ "%s.from_decimal() only takes Decimals, not %r (%s)" %
+ (cls.__name__, dec, type(dec).__name__))
if not dec.is_finite():
# Catches infinities and nans.
- raise TypeError("Cannot convert %s to Fraction." % dec)
+ raise TypeError("Cannot convert %s to %s." % (dec, cls.__name__))
sign, digits, exp = dec.as_tuple()
digits = int(''.join(map(str, digits)))
if sign:
digits = -digits
if exp >= 0:
- return Fraction(digits * 10 ** exp)
+ return cls(digits * 10 ** exp)
else:
- return Fraction(digits, 10 ** -exp)
+ return cls(digits, 10 ** -exp)
def limit_denominator(self, max_denominator=1000000):
"""Closest Fraction to self with denominator at most max_denominator.
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