Python數學實現二元一次方程

import cmath
import  math
import  sys

def get_float(msg,allow_zero):
    x = None
    while x is None:
        try:
            x = float(input(msg))
            if not allow_zero and abs(x) <sys.float_info.epsilon:
                print("zero is not allowed")
                x = None
        except ValueError as err:
            print(err)
    return x

print("ax\N{SUPERSCRIPT TWO} +bx +c = 0")
a = get_float("enter a:", False)
b = get_float("enter b:", True)
c = get_float("enter c:", True)
x1 = None
x2 = None
discriminant = (b**2)-(4*a*c)
if discriminant == 0:
    x1 = -(b/(2*a))
else:
    if discriminant >0:
        root  = math.sqrt(discriminant)
    else:
        root = cmath.sqrt(discriminant)

    x1 = (-b+root) / (2*a)
    x2 = (-b -root) /(2*a)

equation = ("{0}x\N{SUPERSCRIPT TWO}+{1}+{2} = 0""\N{RIGHTWARDS ARROW}X = {3}").format(a,b,c,x1)
if x2 is not None:
    equation += "  or x = {0}".format(x2)
print(equation)