如何在Python中获得更精确的十进制值[重复]

使用十进制模块：

from decimal import Decimala = Decimal('1E-8')b = 10c = Decimal('1E-8')x1 = ((-b)-((b**2)-(4*a*c)).sqrt())/(2*a)x2 = ((-b)+((b**2)-(4*a*c)).sqrt())/(2*a)print 'x1 = {}'.format(x1)print 'x2 = {}'.format(x2)

结果是

x1 = -999999999.999999999000000000x2 = -1.0000000000E-9