newton method 求解平方根

#!/usr/bin/python

def sqrt_iter(guess,x):
    if(good_enough(guess, x)):
        print guess
    else:
        sqrt_iter(improve(guess, x),x)

def improve(guess, x):
    return average(guess, x/guess)

def average(x,y):
     return (x+y)/2

def good_enough(guess,x):
    if(abs(guess * guess -x) < 0.0001):
        return True
    else:
        return False

def sqrt_oliver(x):
    sqrt_iter(1.0,x)

sqrt_oliver(5)

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