20.Scrapy-FormRequest-Post请求

class BaidufanyiSpider(scrapy.Spider):
    name = 'baidufanyi'
    allowed_domains = ['www.baidu.com']

    # post请求时start_urls 没用，parse方法没用
    # start_urls = ['http://www.baidu.com/']
    # def parse(self, response):
    #     pass

    def start_requests(self):
        url = "https://fanyi.baidu.com/sug"
        data = {
            "kw": "love"
        }
        yield scrapy.FormRequest(url=url,
                                 method="post",
                                 formdata=data,
                                 # 如果需要多次提交表单，且url一样，那么就必须加此参数dont_filter，防止被当成重复网页过滤掉了
                                 dont_filter=False,
                                 callback=self.parse_second,
                                 meta={})

    def parse_second(self, response):
        content = response.text
        obj = json.loads(content, encoding="utf8")
        print(obj)