Метод простой итерации Python

import math
class Function():
    def f(self, x):
        return math.log(abs(x+1)) - 2*math.pow(x, 2) + 1
class FixedPointIteration():
    def g(self, x):
        return math.exp(2*math.pow(x, 2) - 1) - 1
 
    def fixedPointIter(self, x0, e, N, f, g):
        step = 1
        flag = 1
        condition = True
        x1 = 0
        while condition:
            x1 = g(x0)
            x0 = x1
            step = step + 1
            if step > N:
                flag = 0
                break
            condition = abs(f(x1))/9 > e
        return x1
func = Function()
fix = FixedPointIteration()
variant = input("Enter the name of method:\nHI - Half Interval Method\nNM - Newton`s Method\nFPI- Fixed Point Iteration\n")
if variant == "FPI":
    x2 = fix.fixedPointIter(0.9, 0.00001, 1000000, func.f, fix.g)
    y2 = fix.fixedPointIter(-0.5, 0.00001, 1000000, func.f, fix.g)
    print("The first root is: " + str(x2))
    print("F(x1) is: " + str(math.ceil(func.f(x2))))
    print("The second root is: " + str(x2))
    print("F(x2) is: " + str(math.ceil(func.f(y2))))

import math
class Function():
    def f(self, x):
        return math.log(abs(x+1)) - 2*math.pow(x, 2) + 1
class FixedPointIteration():
    def g(self, x):
        return 1 / (1/(1 + x) - 4*x)
 
    def fixedPointIter(self, x0, e, N, f, g):
        step = 1
        flag = 1
        condition = True
        x1 = x0
        k = g(x0)
        while condition:
            x0 = x1
            x1 -= f(x0)*k
            step = step + 1
            if step > N:
                flag = 0
                break
            condition = abs(x1 - x0) > e
        return x1
func = Function()
fix = FixedPointIteration()
variant = input("Enter the name of method:\nHI - Half Interval Method\nNM - Newton`s Method\nFPI- Fixed Point Iteration\n")
if variant == "FPI":
    x2 = fix.fixedPointIter(0.9, 0.00001, 1000000, func.f, fix.g)
    print("The first root is: " + str(x2))
    print("F(x1) is: " + str(math.ceil(func.f(x2))))
    
    y2 = fix.fixedPointIter(-0.5, 0.00001, 1000000, func.f, fix.g)
    print("The second root is: " + str(y2))
    print("F(x2) is: " + str(math.ceil(func.f(y2))))