I did the following: 

First I created the function:

def invoiceRegisterPayment(self,register_payment_row):        
    confirm_result = self.ODOO_OBJECT.execute_kw(
        self.DATA, 
        self.UID, 
        self.PASS, 
        'account.payment', 
        'action_validate_invoice_payment', 
        register_payment_row)        
    return confirm_result

    register_payment_row = [
        [payment_id],
        {
            "active_id":invoice_id,
            "active_ids":[invoice_id],
            "active_model": "account.invoice",
            "default_invoice_ids":[[4,invoice_id,None]],
            "journal_type":"sale",
            "lang":"en_US",
            "search_disable_custom_filters": True,
            "type": "out_invoice",
            "tz": False,
            "uid": 2
        } ]

But it shows the following error: "This method should only be called to process a single invoice's payment."

This is the print of register_payment_row:

[[67], {'active_id': 119, 'active_ids': [119], 'active_model': 'account.invoice', 'default_invoice_ids': [4, 119, None], 'journal_type': 'sale', 'lang': 'en_US', 'search_disable_custom_filters': True, 'type': 'out_invoice', 'tz': False, 'uid': 2}]