(ROUND_HALF_UP)策略,是通常习惯使用的四舍五入模式。 (Values are rounded to the closest multiple of 10 to the power minus ndigits; if two multiples are equally close, rounding is done away from 0 ) 而在Python3中,round函数的取舍方式使用靠 近最近和等距靠近偶数 ‾ \underline{靠近最近和等距...
logb([context]):对非 0 对象,返回一个 Decimal 对象,值为调整后的指数。若为 0,则返回 Decimal('-Infinity'),同时 DivisionByZero 标志被激活 next_minus([context]),next_plus([context]),next_toward(other[, context]):分别返回在特定 context 下,最大的不超过对象的值,最小的超过对象的值,最接近的...
"-Infinity",表明操作数是负无穷大。 "-Normal",表明该操作数是一个负的正常数。 "-Subnormal"表明操作数是负数和低于正常的。 "-Zero",表明操作数是负零。 "+Zero",表明操作数是一个正的零。 "+Subnormal",表明操作数是正的和低于正常的。 "+Normal",表示操作数是正数。
sign ::="+"|"-"infinity ::="Infinity"|"inf"nan ::="nan"numeric_value ::= floatnumber | infinity |nan numeric_string ::= [sign] numeric_value Here floatnumber is the form of a Python floating-point literal, described in Floating point literals. Case is not significant, so, for exa...
(values are rounded to the closest multiple of 10 to the power minus ndigits; if two multiples are equally close, rounding is done toward the even choice) 同时,float类型采用双精度二进制存储(参照IEEE754标准),在表示十进制数值时会产生舍入,round函数针对十进制处理舍入,其中会产生一些计算中的诡异...
But if one of the operands is negative, the result is floored, i.e., rounded away from zero (towards negative infinity) − 9//2 = 4 and 9.0//2.0 = 4.0, -11//3 = -4, -11.0//3 = -4.0 Python Comparison Operators These operators compare the values on either sides of them and...
a=1.00E400print(a,type(a))a=float("Infinity")print(a,type(a)) 它将产生以下输出 inf<class'float'>inf<class'float'> 另一个这样的实体是 Nan(代表非数字)。它表示任何未定义或不可表示的值。 >>> a=float('Nan') >>> a Nan Python 复数 ...
Decimal('Infinity')>>> Decimal.from_float(float('-inf')) Decimal('-Infinity')3.1 新版功能.fma(other, third, context=None)混合乘法加法。 返回 self*other+third ,中间乘积 self*other 没有四舍五入。>>> Decimal(2).fma(3, 5) Decimal('11')is_canonical()如果参数是规范的,则为返回 True,...
The function accepts an irrational number, converts it to a fraction, and finds a different fraction with fewer decimal digits. The Python set prevents yielding duplicate values by keeping historical data, and the itertools module’s count() iterator counts to infinity....
In addition to these, cmath provides two complex counterparts for NaN (not a number) and infinity, with both having zero real parts:Python >>> from cmath import nanj, infj >>> nanj.real, nanj.imag (0.0, nan) >>> infj.real, infj.imag (0.0, inf) ...