运行提示SyntaxError: 'yield' outside function

# -*- coding: utf-8 -*-
from typing import Any, Union
import scrapy
from scrapy import Item
from urllib3.util import response
class StockSpider(scrapy.Spider):
name = 'stock'
allowed_domains = ['quote.stockstar.com']
start_urls = ['http://quote.stockstar.com/']
def parse(self, response):
pass
import scrapy
from items import StockstarItem, StockstarItemLoader
class StockSpider(scrapy.Spider):
name = 'stock' #定义爬虫名称
allowed_domains = ['quote.stockstar.com'] #定义爬虫域
start_urls = ['http://quote.stockstar.com/stock/ranklist_a_3_1_1.html']
#定义开始爬虫链接
def parse (self, response) : #撰写爬虫逻辑
page = int (response.url.split("_")[-1].split(".")[0])#抓取页码
item_nodes = response.css('#datalist tr')
for item_node in item_node:
#根据item文件中所定义的字段内容，进行字段内容的抓取
item_loader = StockstarItemLoader(item=StockstarItem(), selector = item_node)
item_loader.add_css("code", "td:nth-child(1) a::text")
item_loader.add_css("abbr", "td:nth-child(2) a::text")
item_loader.add_css("last_trade", "td:nth-child(3) span::text")
item_loader.add_css("chg_ratio", "td:nth-child(4) span::text")
item_loader.add_css("chg_amt", "td:nth-child(5) span::text")
item_loader.add_css("chg_ratio_5min","td:nth-child(6) span::text")
item_loader.add_css("volumn", "td:nth-child(7)::text")
item_loader.add_css ("turn_over", "td:nth-child(8) :: text")
stock_item: Union[Item, Any] = item_loader.load_item()
assert isinstance(stock_item, object)
yield stock_item
if item_node:
next_page = page + 1
next_url = response.url.replace ("{0}.html".format (page) , "{0}.html".format(next_page))
yield scrapy.Request(url=next_url, callback=self.parse)