Fix Decimal.from_float to use valid Python 2.3 syntax, as per
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.
diff --git a/Lib/decimal.py b/Lib/decimal.py
index 88e9bc8..12dd732 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -654,7 +654,8 @@
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):
"""Converts a float to a decimal number, exactly.
@@ -680,11 +681,18 @@
return cls(f)
if _math.isinf(f) or _math.isnan(f): # raises TypeError if not a float
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()
k = d.bit_length() - 1
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):
"""Returns whether the number is not actually one.