#coding=utf-8
import hashlib

hash_len = 32*4

def hex2bin(hex_str):
    global hash_len
    res = ""
    dec_num = int(hex_str,16)
    bin_str = bin(dec_num)[2:]
    return ('0'*(hash_len-len(bin_str)))+ bin_str

def Getmd5(s):
    tmp = hashlib.md5()
    tmp.update(s)
    return hex2bin(tmp.hexdigest())

def SimHash(_str):
    global hash_len
    _sum = [0] * hash_len
    for ch in _str:
        num_list = [int(ch=='1')*2-1 for ch in list(Getmd5(ch))]
        for i in range(len(num_list)):
            _sum[i] += num_list[i]
    hash_num = "".join(map(lambda x:str(int(x >= 0)),_sum))
    # return int(finger_print,2)
    return hash_num

def HammingDistinct(bin_str1, bin_str2):
    tmp = int(bin_str1,2) ^ int(bin_str2,2)
    ct = 0
    while tmp != 0:
        ct += tmp & 0x01
        tmp = tmp >> 1
    return ct


if __name__ == "__main__":
    s1 = "this is a hell"
    s2 = "that is an apple"
    s3 = "hello world"
    print HammingDistinct(SimHash(s1),SimHash(s2))
    print HammingDistinct(SimHash(s2),SimHash(s3))
    print HammingDistinct(SimHash(s1),SimHash(s3))