本文整理汇总了Python中fractions.Fraction.from_decimal方法的典型用法代码示例。如果您正苦于以下问题：Python Fraction.from_decimal方法的具体用法？Python Fraction.from_decimal怎么用？Python Fraction.from_decimal使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类fractions.Fraction的用法示例。
在下文中一共展示了Fraction.from_decimal方法的3个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: exact_ratio
# 需要导入模块: from fractions import Fraction [as 别名]
# 或者: from fractions.Fraction import from_decimal [as 别名]
def exact_ratio(x):
"""Convert Real number x exactly to (numerator, denominator) pair.
x is expected to be an int, Fraction, Decimal or float.
"""
try:
try:
# int, Fraction
return x.numerator, x.denominator
except AttributeError:
# float
try:
return x.as_integer_ratio()
except AttributeError:
# Decimal
try:
return decimal_to_ratio(x)
except AttributeError:
msg = "can't convert type '{}' to numerator/denominator"
raise TypeError(msg.format(type(x).__name__))
except (OverflowError, ValueError):
# INF or NAN
return (x, None)
# FIXME This is faster than Fraction.from_decimal, but still too slow. 示例2: _exact_ratio
# 需要导入模块: from fractions import Fraction [as 别名]
# 或者: from fractions.Fraction import from_decimal [as 别名]
def _exact_ratio(x):
"""Convert Real number x exactly to (numerator, denominator) pair.
>>> _exact_ratio(0.25)
(1, 4)
x is expected to be an int, Fraction, Decimal or float.
"""
try:
try:
# int, Fraction
return (x.numerator, x.denominator)
except AttributeError:
# float
try:
return x.as_integer_ratio()
except AttributeError:
# Decimal
try:
return _decimal_to_ratio(x)
except AttributeError:
msg = "can't convert type '{}' to numerator/denominator"
raise TypeError(msg.format(type(x).__name__)) from None
except (OverflowError, ValueError):
# INF or NAN
if __debug__:
# Decimal signalling NANs cannot be converted to float :-(
if isinstance(x, Decimal):
assert not x.is_finite()
else:
assert not math.isfinite(x)
return (x, None)
# FIXME This is faster than Fraction.from_decimal, but still too slow. 示例3: _exact_ratio
# 需要导入模块: from fractions import Fraction [as 别名]
# 或者: from fractions.Fraction import from_decimal [as 别名]
def _exact_ratio(x):
"""Return Real number x to exact (numerator, denominator) pair.
>>> _exact_ratio(0.25)
(1, 4)
x is expected to be an int, Fraction, Decimal or float.
"""
try:
# Optimise the common case of floats. We expect that the most often
# used numeric type will be builtin floats, so try to make this as
# fast as possible.
if type(x) is float:
return x.as_integer_ratio()
try:
# x may be an int, Fraction, or Integral ABC.
return (x.numerator, x.denominator)
except AttributeError:
try:
# x may be a float subclass.
return x.as_integer_ratio()
except AttributeError:
try:
# x may be a Decimal.
return _decimal_to_ratio(x)
except AttributeError:
# Just give up?
pass
except (OverflowError, ValueError):
# float NAN or INF.
assert not math.isfinite(x)
return (x, None)
msg = "can't convert type '{}' to numerator/denominator"
raise TypeError(msg.format(type(x).__name__))
# FIXME This is faster than Fraction.from_decimal, but still too slow.