python实现java的hashcod

def convert_n_bytes(n, b):

bits = b * 8

return (n + 2 ** (bits - 1)) % 2 ** bits - 2 ** (bits - 1)

def convert_4_bytes(n):

return convert_n_bytes(n, 4)

def getHashCode(s):

h = 0

n = len(s)

for i, c in enumerate(s):

h = h + ord(c) * 31 ** (n - 1 - i)

return convert_4_bytes(h)