mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-09-26 18:29:57 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 10

Fix Decimal.from_float to use valid Python 2.3 syntax, as per

Browse source 
comments at top of decimal.py.  (But note that the from_float
method itself with still not be usable before Python 2.7.)
See issue 4796 for discussion.
This commit is contained in:
Mark Dickinson 2009-01-04 21:10:56 +00:00
parent 1de3327015
commit 6a961637a8
1 changed files with 11 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

14
Lib/decimal.py
View file

@ -654,7 +654,8 @@ class Decimal(object):
raise TypeError("Cannot convert %r to Decimal" % value) raise TypeError("Cannot convert %r to Decimal" % value)
@classmethod # @classmethod, but @decorator is not valid Python 2.3 syntax, so
# don't use it (see notes on Py2.3 compatibility at top of file)
def from_float(cls, f): def from_float(cls, f):
"""Converts a float to a decimal number, exactly. """Converts a float to a decimal number, exactly.
@ -680,11 +681,18 @@ class Decimal(object):
return cls(f) return cls(f)
if _math.isinf(f) or _math.isnan(f): # raises TypeError if not a float if _math.isinf(f) or _math.isnan(f): # raises TypeError if not a float
return cls(repr(f)) return cls(repr(f))
sign = 0 if _math.copysign(1.0, f) == 1.0 else 1 if _math.copysign(1.0, f) == 1.0:
sign = 0
else:
sign = 1
n, d = abs(f).as_integer_ratio() n, d = abs(f).as_integer_ratio()
k = d.bit_length() - 1 k = d.bit_length() - 1
result = _dec_from_triple(sign, str(n*5**k), -k) result = _dec_from_triple(sign, str(n*5**k), -k)
return result if cls is Decimal else cls(result) if cls is Decimal:
return result
else:
return cls(result)
from_float = classmethod(from_float)
def _isnan(self): def _isnan(self):
"""Returns whether the number is not actually one. """Returns whether the number is not actually one.