Newton's method in Python.

def square(x): return x * x

def cube(x): return x * square(x)

def f1(x): return cube(x) - 2 * x - 5

def dfdx1(x): return 3 * square(x) - 2

def f2(x): return cube(x) * cube(x) -2

def dfdx2(x): return 5 * cube(x) * square(x)

return the approximation of f(x) = 0 when 2 consecutive guesses give

same value.

def newton_raphson(x,f,dfdx):
x = float(x)
print x
x1 = x - f(x)/dfdx(x)
while ????:
    print x1
    x2 = x1 - f(x1)/dfdx(x1)
    x1 = x2

I am quite new to programming and quite unsure how to make this one work :( i have followed a tutorial on defining functions, but the body, i just cant seen to get it to give me the desired result, i know there are other people who have posted on here about newtons method, but i don't want to copy their code.