x = 25
epsilon = 0.01
numguess = 0
low = 0.0
high = max(1.0,x)
ans = (high + low )/2
while abs(ans**2 -x ) >=epsilon:
numguess +=1
if ans**2 < x:
low = ans
else:
high = ans
ans = (high + low )/2.0
print(ans, ‘is close to square root of ‘, x )
原文：https://www.cnblogs.com/astride/p/13267729.html