Python 2's hash() function in Python 3

hash_py2.py

"""
Implementation of hash() differs in Python 2 and Python 3
To use Python 2's hash() in Python 3, use the following snippet.
Note that this snippet computes the expected hash only of input of type str
Source: https://www.laurentluce.com/posts/python-dictionary-implementation/
"""
import numpy as np

def str_hash(string):
    x = np.array([ord(string[0]) << 7], dtype=int)
    if not string:
        return 0 # empty
    for char in string:
        x[0] = (1000003 * x[0]) ^ ord(char)
    x[0] = x[0] ^ len(string)
    return x[0]