[Python] 정확하고 작은 수가 필요할 때 - decimal

decimal.getcontext().prec = 50
decimal.getcontext().rounding = decimal.ROUND_HALF_UP

if value < decimal.Decimal(1e-9) and value > decimal.Decimal(-1e-9):

 

pi = Decimal('3.14159265358979323846264338327950288419716939937510')

def sin(x):
    x = x % (2 * pi)
    getcontext().prec += 2
    i, lasts, s, fact, num, sign = 1, 0, x, 1, x, 1
    while s != lasts:
        lasts = s
        i += 2
        fact *= i * (i - 1)
        num *= x * x
        sign *= -1
        s += num / fact * sign
    getcontext().prec -= 2
    return +s