简要说明：
我有一个Scrapy项目，从雅虎获取股票数据金融。为了让我的项目有效，我需要确保库存已经存在了一段时间。我首先通过刮掉CAT（卡特彼勒公司（CAT）-NYSE），获得该时间段的收盘价格，然后确保所有被冻结的股票与CAT的收盘价相同从而确保股票在期望的时间长度内公开交易。
问题：
这一切都很好用，但我的问题是在scrapy完成解析CAT之前，它开始抓取其他股票并解析它们。这导致错误，因为之前我可以从CAT获得所需的收盘价格，scrapy正试图决定是否有任何其他股票的收盘价格与CAT相同，但尚不存在。
实际问题
如何强制scrapy在开始其他人之前完成解析一个网址
我也尝试过：
def start_requests(self):
global start_time
yield Request('http://finance.yahoo.com/q?s=CAT', self.parse)
# Waits 4 seconds to allow CAT to finish crawling
if time.time() - start_time > 0.2:
for i in self.other_urls:
yield Request(i, self.parse)
但other_urls中的股票从未开始，因为scrapy永远不会回到def start_requests来检查时间是否高于0.2
整个代码：
from scrapy.selector import Selector
from scrapy import Request
from scrapy.exceptions import CloseSpider
from sharpeparser.gen_settings import *
from decimal import Decimal
from scrapy.spider import Spider
from sharpeparser.items import SharpeparserItem
import numpy
import time
if data_intervals == "m":
required_amount_of_returns = 24
elif data_intervals == "w":
required_amount_of_returns = 100
else:
required_amount_of_returns =
counter = 1
start_time = time.time()
class DnotSpider(Spider):
# ---- >>> ENSURE YOU INDENT 1 ---- >>>
# =======================================
name = "dnot"
allowed_domains = ["finance.yahoo.com", "http://eoddata.com/", "ca.finance.yahoo.com"]
start_urls = ['http://finance.yahoo.com/q?s=CAT']
other_urls = ['http://eoddata.com/stocklist/TSX.htm', 'http://eoddata.com/stocklist/TSX/B.htm', 'http://eoddata.com/stocklist/TSX/C.htm', 'http://eoddata.com/stocklist/TSX/D.htm', 'http://eoddata.com/stocklist/TSX/E.htm', 'http://eoddata.com/stocklist/TSX/F.htm', 'http://eoddata.com/stocklist/TSX/G.htm', 'http://eoddata.com/stocklist/TSX/H.htm', 'http://eoddata.com/stocklist/TSX/I.htm', 'http://eoddata.com/stocklist/TSX/J.htm', 'http://eoddata.com/stocklist/TSX/K.htm', 'http://eoddata.com/stocklist/TSX/L.htm', 'http://eoddata.com/stocklist/TSX/M.htm', 'http://eoddata.com/stocklist/TSX/N.htm', 'http://eoddata.com/stocklist/TSX/O.htm', 'http://eoddata.com/stocklist/TSX/P.htm', 'http://eoddata.com/stocklist/TSX/Q.htm', 'http://eoddata.com/stocklist/TSX/R.htm', 'http://eoddata.com/stocklist/TSX/S.htm', 'http://eoddata.com/stocklist/TSX/T.htm', 'http://eoddata.com/stocklist/TSX/U.htm', 'http://eoddata.com/stocklist/TSX/V.htm', 'http://eoddata.com/stocklist/TSX/W.htm', 'http://eoddata.com/stocklist/TSX/X.htm', 'http://eoddata.com/stocklist/TSX/Y.htm', 'http://eoddata.com/stocklist/TSX/Z.htm'
'http://eoddata.com/stocklist/NASDAQ/B.htm', 'http://eoddata.com/stocklist/NASDAQ/C.htm', 'http://eoddata.com/stocklist/NASDAQ/D.htm', 'http://eoddata.com/stocklist/NASDAQ/E.htm', 'http://eoddata.com/stocklist/NASDAQ/F.htm', 'http://eoddata.com/stocklist/NASDAQ/G.htm', 'http://eoddata.com/stocklist/NASDAQ/H.htm', 'http://eoddata.com/stocklist/NASDAQ/I.htm', 'http://eoddata.com/stocklist/NASDAQ/J.htm', 'http://eoddata.com/stocklist/NASDAQ/K.htm', 'http://eoddata.com/stocklist/NASDAQ/L.htm', 'http://eoddata.com/stocklist/NASDAQ/M.htm', 'http://eoddata.com/stocklist/NASDAQ/N.htm', 'http://eoddata.com/stocklist/NASDAQ/O.htm', 'http://eoddata.com/stocklist/NASDAQ/P.htm', 'http://eoddata.com/stocklist/NASDAQ/Q.htm', 'http://eoddata.com/stocklist/NASDAQ/R.htm', 'http://eoddata.com/stocklist/NASDAQ/S.htm', 'http://eoddata.com/stocklist/NASDAQ/T.htm', 'http://eoddata.com/stocklist/NASDAQ/U.htm', 'http://eoddata.com/stocklist/NASDAQ/V.htm', 'http://eoddata.com/stocklist/NASDAQ/W.htm', 'http://eoddata.com/stocklist/NASDAQ/X.htm', 'http://eoddata.com/stocklist/NASDAQ/Y.htm', 'http://eoddata.com/stocklist/NASDAQ/Z.htm',
'http://eoddata.com/stocklist/NYSE/B.htm', 'http://eoddata.com/stocklist/NYSE/C.htm', 'http://eoddata.com/stocklist/NYSE/D.htm', 'http://eoddata.com/stocklist/NYSE/E.htm', 'http://eoddata.com/stocklist/NYSE/F.htm', 'http://eoddata.com/stocklist/NYSE/G.htm', 'http://eoddata.com/stocklist/NYSE/H.htm', 'http://eoddata.com/stocklist/NYSE/I.htm', 'http://eoddata.com/stocklist/NYSE/J.htm', 'http://eoddata.com/stocklist/NYSE/K.htm', 'http://eoddata.com/stocklist/NYSE/L.htm', 'http://eoddata.com/stocklist/NYSE/M.htm', 'http://eoddata.com/stocklist/NYSE/N.htm', 'http://eoddata.com/stocklist/NYSE/O.htm', 'http://eoddata.com/stocklist/NYSE/P.htm', 'http://eoddata.com/stocklist/NYSE/Q.htm', 'http://eoddata.com/stocklist/NYSE/R.htm', 'http://eoddata.com/stocklist/NYSE/S.htm', 'http://eoddata.com/stocklist/NYSE/T.htm', 'http://eoddata.com/stocklist/NYSE/U.htm', 'http://eoddata.com/stocklist/NYSE/V.htm', 'http://eoddata.com/stocklist/NYSE/W.htm', 'http://eoddata.com/stocklist/NYSE/X.htm', 'http://eoddata.com/stocklist/NYSE/Y.htm', 'http://eoddata.com/stocklist/NYSE/Z.htm',
'http://eoddata.com/stocklist/HKEX/0.htm', 'http://eoddata.com/stocklist/HKEX/1.htm', 'http://eoddata.com/stocklist/HKEX/2.htm', 'http://eoddata.com/stocklist/HKEX/3.htm', 'http://eoddata.com/stocklist/HKEX/6.htm', 'http://eoddata.com/stocklist/HKEX/8.htm',
'http://eoddata.com/stocklist/LSE/0.htm', 'http://eoddata.com/stocklist/LSE/1.htm', 'http://eoddata.com/stocklist/LSE/2.htm', 'http://eoddata.com/stocklist/LSE/3.htm', 'http://eoddata.com/stocklist/LSE/4.htm', 'http://eoddata.com/stocklist/LSE/5.htm', 'http://eoddata.com/stocklist/LSE/6.htm', 'http://eoddata.com/stocklist/LSE/7.htm', 'http://eoddata.com/stocklist/LSE/8.htm', 'http://eoddata.com/stocklist/LSE/9.htm', 'http://eoddata.com/stocklist/LSE/A.htm', 'http://eoddata.com/stocklist/LSE/B.htm', 'http://eoddata.com/stocklist/LSE/C.htm', 'http://eoddata.com/stocklist/LSE/D.htm', 'http://eoddata.com/stocklist/LSE/E.htm', 'http://eoddata.com/stocklist/LSE/F.htm', 'http://eoddata.com/stocklist/LSE/G.htm', 'http://eoddata.com/stocklist/LSE/H.htm', 'http://eoddata.com/stocklist/LSE/I.htm', 'http://eoddata.com/stocklist/LSE/G.htm', 'http://eoddata.com/stocklist/LSE/K.htm', 'http://eoddata.com/stocklist/LSE/L.htm', 'http://eoddata.com/stocklist/LSE/M.htm', 'http://eoddata.com/stocklist/LSE/N.htm', 'http://eoddata.com/stocklist/LSE/O.htm', 'http://eoddata.com/stocklist/LSE/P.htm', 'http://eoddata.com/stocklist/LSE/Q.htm', 'http://eoddata.com/stocklist/LSE/R.htm', 'http://eoddata.com/stocklist/LSE/S.htm', 'http://eoddata.com/stocklist/LSE/T.htm', 'http://eoddata.com/stocklist/LSE/U.htm', 'http://eoddata.com/stocklist/LSE/V.htm', 'http://eoddata.com/stocklist/LSE/W.htm', 'http://eoddata.com/stocklist/LSE/X.htm', 'http://eoddata.com/stocklist/LSE/Y.htm', 'http://eoddata.com/stocklist/LSE/Z.htm',
'http://eoddata.com/stocklist/AMS/A.htm', 'http://eoddata.com/stocklist/AMS/B.htm', 'http://eoddata.com/stocklist/AMS/C.htm', 'http://eoddata.com/stocklist/AMS/D.htm', 'http://eoddata.com/stocklist/AMS/E.htm', 'http://eoddata.com/stocklist/AMS/F.htm', 'http://eoddata.com/stocklist/AMS/G.htm', 'http://eoddata.com/stocklist/AMS/H.htm', 'http://eoddata.com/stocklist/AMS/I.htm', 'http://eoddata.com/stocklist/AMS/J.htm', 'http://eoddata.com/stocklist/AMS/K.htm', 'http://eoddata.com/stocklist/AMS/L.htm', 'http://eoddata.com/stocklist/AMS/M.htm', 'http://eoddata.com/stocklist/AMS/N.htm', 'http://eoddata.com/stocklist/AMS/O.htm', 'http://eoddata.com/stocklist/AMS/P.htm', 'http://eoddata.com/stocklist/AMS/Q.htm', 'http://eoddata.com/stocklist/AMS/R.htm', 'http://eoddata.com/stocklist/AMS/S.htm', 'http://eoddata.com/stocklist/AMS/T.htm', 'http://eoddata.com/stocklist/AMS/U.htm', 'http://eoddata.com/stocklist/AMS/V.htm', 'http://eoddata.com/stocklist/AMS/W.htm', 'http://eoddata.com/stocklist/AMS/X.htm', 'http://eoddata.com/stocklist/AMS/Y.htm', 'http://eoddata.com/stocklist/AMS/Z.htm',
'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=A', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=B', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=C', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=D', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=E', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=F', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=G', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=H', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=I', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=J', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=K', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=L', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=M', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=N', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=O', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=P', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=Q', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=R', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=S', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=T', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=U', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=V', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=W', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=X', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=Y', 'https://ca.finance.yahoo.com/q/cp?s=%5EIXIC&alpha=Z',
'https://ca.finance.yahoo.com/q/cp?s=%5EHSI&alpha=0', 'https://ca.finance.yahoo.com/q/cp?s=%5EHSI&alpha=1', 'https://ca.finance.yahoo.com/q/cp?s=%5EHSI&alpha=2', 'https://ca.finance.yahoo.com/q/cp?s=%5EHSI&alpha=3',
'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=A', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=B', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=C', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=D', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=E', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=F', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=G', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=H', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=I', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=J', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=K', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=L', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=M', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=N', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=O', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=P', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=Q', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=R', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=S', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=T', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=U', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=V', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=W', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=X', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=Y', 'http://finance.yahoo.com/q/cp?s=%5EN100&alpha=Z',
'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=A', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=B', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=C', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=D', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=E', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=F', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=G', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=H', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=I', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=J', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=K', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=L', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=M', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=N', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=O', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=P', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=Q', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=R', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=S', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=T', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=U', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=V', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=W', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=X', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=Y', 'http://finance.yahoo.com/q/cp?s=%5EFCHI&alpha=Z',
'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=A', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=B', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=C', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=D', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=E', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=F', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=G', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=H', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=I', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=J', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=K', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=L', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=M', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=N', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=O', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=P', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=Q', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=R', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=S', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=T', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=U', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=V', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=W', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=X', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=Y', 'http://finance.yahoo.com/q/cp?s=%5EAEX&alpha=Z']
def start_requests(self):
global start_time
yield Request('http://finance.yahoo.com/q?s=CAT', self.parse)
# Waits 4 seconds to allow CAT to finish crawling
if time.time() - start_time > 0.2:
for i in self.other_urls:
yield Request(i, self.parse)
def parse(self, response):
if "eoddata" in response.url:
companyList = response.xpath('//tr[@class="ro"]/td/a/text()').extract()
for company in companyList:
if "TSX" in response.url:
go = 'http://finance.yahoo.com/q/hp?s={0}.TO&a={1}&b={2}&c={3}&d={4}&e={5}&f={6}&g={7}'.format(company, beginning_month, beginning_day, beginning_year, ending_month, ending_day, ending_year, data_intervals)
yield Request(go, self.stocks1)
elif "LSE" in response.url:
go = 'http://finance.yahoo.com/q/hp?s={0}.L&a={1}&b={2}&c={3}&d={4}&e={5}&f={6}&g={7}'.format(company, beginning_month, beginning_day, beginning_year, ending_month, ending_day, ending_year, data_intervals)
yield Request(go, self.stocks1)
elif "HKEX" in response.url:
go = 'http://finance.yahoo.com/q/hp?s={0}.HK&a={1}&b={2}&c={3}&d={4}&e={5}&f={6}&g={7}'.format(company, beginning_month, beginning_day, beginning_year, ending_month, ending_day, ending_year, data_intervals)
yield Request(go, self.stocks1)
elif "AMS" in response.url:
go = 'https://ca.finance.yahoo.com/q/hp?s={0}.AS&a={1}&b={2}&c={3}&d={4}&e={5}&f={6}&g={7}'.format(company, beginning_month, beginning_day, beginning_year, ending_month, ending_day, ending_year, data_intervals)
yield Request(go, self.stocks1)
else:
go = 'https://ca.finance.yahoo.com/q/hp?s={0}&a={1}&b={2}&c={3}&d={4}&e={5}&f={6}&g={7}'.format(company, beginning_month, beginning_day, beginning_year, ending_month, ending_day, ending_year, data_intervals)
yield Request(go, self.stocks1)
elif "http://finance.yahoo.com/q?s=CAT" in response.url:
go = 'http://finance.yahoo.com/q/hp?s=CAT&a={0}&b={1}&c={2}&d={3}&e={4}&f={5}&g={6}'.format(beginning_month, beginning_day, beginning_year, ending_month, ending_day, ending_year, data_intervals)
yield Request(go, self.stocks1)
else:
rows = response.xpath('//table[@class="yfnc_tableout1"]//table/tr')[1:]
for row in rows:
company = row.xpath('.//td[1]/b/a/text()').extract()
go = 'http://finance.yahoo.com/q/hp?s={0}&a={1}&b={2}&c={3}&d={4}&e={5}&f={6}&g={7}'.format(company, beginning_day, beginning_month, beginning_year, ending_day, ending_month, ending_year, data_intervals)
yield Request(go, self.stocks1)
def stocks1(self, response):
current_page = response.url
print current_page
# If the link is not the same as the first page, ie. stocks1 is requested through stocks2, get the stock data from stocks2
if initial_ending not in current_page[-iel:]:
returns_pages = response.meta.get('returns_pages')
# Remove the last stock price from the stock list, because it is the same as the first on the new list
if not not returns_pages:
if len(returns_pages) > 2:
returns_pages = returns_pages[:-1]
else:
# Else, if the link does match that of the first page, create a new list becuase one does not exist yet
returns_pages = []
# This grabs the stock data from the page
rows = response.xpath('//table[@class="yfnc_datamodoutline1"]//table/tr')[1:]
print "stocks1"
print returns_pages
for row in rows:
cells = row.xpath('.//td/text()').extract()
try:
values = cells[-1]
try:
float(values)
# And adds it to returns_pages
returns_pages.append(values)
except ValueError:
continue
except ValueError:
continue
print "after"
print returns_pages
# exp determines if there is a 'Next page' or not
exp = response.xpath('//td[@align="right"]/a[@rel="next"]').extract()
# If there is a 'Next Page':
if not not exp:
# And this is the first page:
if initial_ending in current_page[-iel:]:
#create necessary url for the 2nd page
next_page = current_page + "&z=66&y=66"
# If this is not the first page
else:
# This increases the end of the link by 66, thereby getting the next 66 results on for pages 2 and after
u = int(current_page[-6:].split("=",1)[1])
o = len(str(u))
u += 66
next_page = current_page[:-o] + str(u)
print next_page, "66&y in curr_page"
# Then go back to self.stocks1 to get more data on the next page
yield Request(next_page, self.stocks2, meta={'returns_pages': returns_pages}, dont_filter=True)
# Else, if there is no 'Next Link'
else:
# Send the retuns to finalize.stock to be saved in the item
yield Request(current_page, callback=self.finalize_stock, meta={'returns_pages': returns_pages}, dont_filter=True)
def stocks2(self, response):
# Prints the link of the current url
current_page = response.url
print current_page
# Gets the returns from the previous page
returns_pages = response.meta.get('returns_pages')
# Removes the last return from the previous page because it will be a duplicate
returns_pages = returns_pages[:-1]
print "stocks2"
print returns_pages
# Gets all of the returns on the page
rows = response.xpath('//table[@class="yfnc_datamodoutline1"]//table/tr')[1:]
for row in rows:
cells = row.xpath('.//td/text()').extract()
try:
values = cells[-1]
try:
float(values)
# And adds it to the previous returns
returns_pages.append(values)
except ValueError:
continue
except ValueError:
continue
print "after 2"
print returns_pages
# exp determines if there is a 'Next page' or not
exp = response.xpath('//td[@align="right"]/a[@rel="next"]').extract()
# If there is a 'Next Page':
if not not exp:
# And somehow, this is the first page (should never be true)
if initial_ending in current_page[-iel:]:
# Add necessary link to go to the second page
next_page = current_page + "&z=66&y=66"
print next_page, "66&y not in curr_page"
# Else, this is not the first page (should always be true)
else:
# add 66 to the last number on the preceeding link in order to access the second or later pages
u = int(current_page[-6:].split("=",1)[1])
o = len(str(u))
u += 66
next_page = current_page[:-o] + str(u)
print next_page, "66&y in curr_page"
# go back to self.stocks1 to get more data on the next page
yield Request(next_page, self.stocks1, meta={'returns_pages': returns_pages}, dont_filter=True)
else:
# If there is no "Next" link, send the retuns to finalize.stock to be saved in the item
yield Request(current_page, callback=self.finalize_stock, meta={'returns_pages': returns_pages}, dont_filter=True)
print "sending to finalize stock"
def finalize_stock(self,response):
current_page = response.url
print "====================="
print "finalize_stock called"
print current_page
print "====================="
unformatted_returns = response.meta.get('returns_pages')
returns = [float(i) for i in unformatted_returns]
global required_amount_of_returns, counter
if counter == 1 and "CAT" in response.url:
required_amount_of_returns = len(returns)
elif required_amount_of_returns == 0:
raise CloseSpider("'Error with initiating required amount of returns'")
counter += 1
print counter
# Iterator to calculate Rate of return
# ====================================
if data_intervals == "m":
k = 12
elif data_intervals == "w":
k = 4
else:
k = 30
sub_returns_amount = required_amount_of_returns - k
sub_returns = returns[:sub_returns_amount]
rate_of_return = []
RFR = 0.03
# Make sure list is exact length, otherwise rate_of_return will be inaccurate
# Returns has not been checked by pipeline yet, so small lists will be in the variable
if len(returns) > required_amount_of_returns:
for number in sub_returns:
numerator = number - returns[k]
rate = numerator/returns[k]
if rate == '':
rate = 0
rate_of_return.append(rate)
k += 1
item = SharpeparserItem()
items = []
item['url'] = response.url
item['name'] = response.xpath('//div[@class="title"]/h2/text()').extract()
item['avg_returns'] = numpy.average(rate_of_return)
item['var_returns'] = numpy.cov(rate_of_return)
item['sd_returns'] = numpy.std(rate_of_return)
item['returns'] = unformatted_returns
item['rate_of_returns'] = rate_of_return
item['exchange'] = response.xpath('//span[@class="rtq_exch"]/text()').extract()
item['ind_sharpe'] = ((numpy.average(rate_of_return) - RFR) / numpy.std(rate_of_return))
items.append(item)
yield item
答案 0 :(得分：3)
关于按顺序执行每个请求的实际问题...有几个类似于你的问题：
总的来说，似乎有几个选择：
priority函数中的start_requests()标记按特定顺序迭代网站CONCURRENT_REQUESTS=1以确保一次只执行一个请求CAT自动收录器完成后立即解析所有网站。如果您已使用settings API if函数将上述设置轻推到更高的值
我无法运行您的确切代码，因为您错过了类结构，但我已经看到了一些可能会让您失望的事情：
This SO post描述了yield。为了更好地理解yield函数的工作方式，请执行以下操作：
def it():
yield range(2)
yield range(10)
g = it()
for i in g:
print i
# now the generator has been consumed.
for i in g:
print i
This SO帖子还证明start_requests()函数会覆盖start_urls指定的列表。看来，由于这个原因，start_urls中的网址会被此函数覆盖，该函数只生成Request('http://finance.yahoo.com/q?s=CAT', self.parse)的生成器表达式
是否有任何特殊原因导致您未按照要解析的顺序列出列表start_urls中的所有网址并删除函数start_requests()？ start_urls状态docs：
后续网址将从包含在起始网址
中的数据连续生成
在globals中粘贴内容会导致您在此类项目中出现问题，通常最好将其作为self def __init__(self):的属性启动调用类时将调用的函数。
这可能很小但你可以通过在一个单独的文件中列出所有符号然后在代码中加载它们来节省大量的滚动/努力。就目前而言，你在列表中有很多重复，你可以删除它，使其更容易阅读。