Square root by binary search

sqrt.py

import sys


def sqrt(n):
    low = 0
    high = n
    mid = (high - low) / 2.
    iter = 0

    while abs((mid ** 2) - float(n)) >  0.00001:
        iter += 1
        if (mid ** 2) > n:
            high = mid
            mid = (high - low) /2.
        else:
            low = mid
            mid = mid + ((high - low) / 2.)
    print "iterations", iter

    return mid
try:
    number = int(sys.argv[1])
except:
    number = 2
print sqrt(number), number ** 0.5