def process_orders(self, orderbook):
        ''' Default and costant orders processor. Overwrite it for more
        sophisticated strategies '''
        for stock, alloc in orderbook.iteritems():
            self.logger.info('{}: Ordered {} {} stocks'.format(
                self.datetime, stock, alloc))
            if isinstance(alloc, int):
                self.order(stock, alloc)
            elif isinstance(alloc, float) and \
                    alloc >= -1 and alloc <= 1:
                self.order_percent(stock, alloc)
            else:
                self.logger.warning(
                    '{}: invalid order for {}: {})'
                    .format(self.datetime, stock, alloc))
Default and costant orders processor. Overwrite it for more
        sophisticated strategies