def child(self, index):
    'Returns the child HDPrivateKey at a particular index.\n        Hardened children return for indices >= 0x8000000.\n        '
    if (index >= 2147483648):
        data = (int_to_big_endian(self.private_key.secret, 33) + int_to_big_endian(index, 4))
    else:
        data = (self.private_key.point.sec() + int_to_big_endian(index, 4))
    h = hmac_sha512(self.chain_code, data)
    secret = ((big_endian_to_int(h[:32]) + self.private_key.secret) % N)
    private_key = PrivateKey(secret=secret)
    chain_code = h[32:]
    depth = (self.depth + 1)
    parent_fingerprint = self.fingerprint()
    child_number = index
    return HDPrivateKey(private_key=private_key, chain_code=chain_code, depth=depth, parent_fingerprint=parent_fingerprint, child_number=child_number, testnet=self.testnet)
Returns the child HDPrivateKey at a particular index.
Hardened children return for indices >= 0x8000000.
def child(self, index):
    'Returns the child HDPrivateKey at a particular index.\n        Hardened children return for indices >= 0x8000000.\n        '
    if (index >= 2147483648):
        data = (int_to_big_endian(self.private_key.secret, 33) + int_to_big_endian(index, 4))
    else:
        data = (self.private_key.point.sec() + int_to_big_endian(index, 4))
    h = hmac_sha512(self.chain_code, data)
    secret = ((big_endian_to_int(h[:32]) + self.private_key.secret) % N)
    private_key = PrivateKey(secret=secret)
    chain_code = h[32:]
    depth = (self.depth + 1)
    parent_fingerprint = self.fingerprint()
    child_number = index
    return HDPrivateKey(private_key=private_key, chain_code=chain_code, depth=depth, parent_fingerprint=parent_fingerprint, child_number=child_number, testnet=self.testnet)