Scrapy模拟表单和Ajax发送POST请求

scrapy.FormRequest

普通请求使用scrapy.Request类就可以实现，但是遇到模拟表单或Ajax提交post请求的时候，Request类就不如 子类 FormRequest类方便了，因为他自带 formdata ，专门用来设置表单字段数据，默认method也是POST。

def start_requests(self):
form_data = {'f1':'1', 'f2':'100'}  # 表单数据，字典格式，注意数字也要用引号引起来，否则报错。
yield scrapy.FormRequest(url, formdata=form_data) # 还可以通过callback修改回调函数等

参考:

http://scrapy-chs.readthedocs.io/zh_CN/0.24/topics/request-response.html?highlight=post#formrequest-objects

https://stackoverflow.com/questions/39012902/scrapy-making-request-with-post-method

scrapy.http.FormRequest

还有其他方法，如scrapy.http.FormRequest，但是感觉不如以上方法方便：

return [scrapy.http.FormRequest(
self.myurl,
formdata={'f1':'123','f2':'456'},
callback=self.parse)]

from scrapy.item import Item, Field
from scrapy.http import FormRequest
from scrapy.spider import BaseSpider

class DeltaItem(Item):
title = Field()
link = Field()
desc = Field()

class DmozSpider(BaseSpider):
name = "delta"
allowed_domains = ["delta.com"]
start_urls = ["http://www.delta.com"]

def parse(self, response):
yield FormRequest.from_response(response,
formname='flightSearchForm',
formdata={'departureCity[0]': 'JFK',
'destinationCity[0]': 'SFO',
'departureDate[0]': '07.20.2013',
'departureDate[1]': '07.28.2013'},
callback=self.parse1)

def parse1(self, response):
print response.status

参考：http://www.smipple.net/snippet/fruityworld/scrapy%20post%20request