如何在循环中使用Scrapy FormRequest

import scrapy
from scrapy.http import FormRequest

class MySpider(scrapy.Spider):
    name = 'my_spider'
    
    def start_requests(self):
        # 在这里定义循环的逻辑
        urls = ['http://www.example.com/page1', 'http://www.example.com/page2']
        for url in urls:
            yield scrapy.Request(url=url, callback=self.parse_page)

class MySpider(scrapy.Spider):
    name = 'my_spider'
    
    def start_requests(self):
        # 在这里定义循环的逻辑
        urls = ['http://www.example.com/page1', 'http://www.example.com/page2']
        for url in urls:
            formdata = {
                'username': 'my_username',
                'password': 'my_password'
            }
            yield FormRequest(url=url, formdata=formdata, callback=self.parse_page)

class MySpider(scrapy.Spider):
    name = 'my_spider'
    
    def start_requests(self):
        # 在这里定义循环的逻辑
        urls = ['http://www.example.com/page1', 'http://www.example.com/page2']
        for url in urls:
            formdata = {
                'username': 'my_username',
                'password': 'my_password'
            }
            yield FormRequest(url=url, formdata=formdata, callback=self.parse_page)
    
    def parse_page(self, response):
        # 在这里处理响应数据
        # 可以使用response.xpath或response.css来提取数据
        pass