gistfile1.py

def parse_category(self, response):
    item = Item()
    item['category'] = get_category(response)
    for url in get_product_urls(response):
        yield Request(url, callback=self.parse_product, meta={'item': item.copy()])
        
def parse_product(self, response):
    item = response.meta.get('item', {})
    ...
    return item