scrapy a weird bug code that can't call pipeli

2019-09-16 06:45发布

问题:

I write a small spider, when I run and it can't call pipeline.

After debug for a while, I find the bug code area.

The logic of the spider is that I crawl the first url to fetch cookie, then I crawl the second url to download the code picture with cookie, and I post some data I prepare to the third url. And If the text I get from the picture wrong then I download again to post the third url repeatedly, until I got the right text.

Let me show you the code:

# -*- coding: gbk -*-
import scrapy
from scrapy.http import FormRequest
import json
import os
from datetime import datetime
from scrapy.selector import Selector
from teacherCourse.handlePic import handle
from teacherCourse.items import DetailProfItem
from teacherCourse.items import DetailProfCourseItem
from teacherCourse.items import containItem

class GetTeacherCourseSpider(scrapy.Spider):
    name = 'TeacherCourse'
#    custom_settings = {
#            'ITEM_PIPELINES': {
#                'teacherCourse.pipelines.TeacherCoursePipeline': 300,
#                }
#            }

    def __init__(self, selXNXQ='', titleCode=''):
        self.getUrl = 'http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB.aspx' # first
        self.vcodeUrl = 'http://jwxt.dgut.edu.cn/jwweb/sys/ValidateCode.aspx' # second
        self.postUrl = 'http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB_rpt.aspx' # third
        self.findSessionId = None # to save the cookies
        self.XNXQ = selXNXQ
        self.titleCode = titleCode

    def start_requests(self):
        request = scrapy.Request(self.getUrl,
               callback = self.downloadPic)
        yield request

    def downloadPic(self, response):
        # download the picture
        # find the session id
        self.findSessionId = response.headers.getlist('Set-Cookie')[0].decode().split(";")[0].split("=")
        request = scrapy.Request(self.vcodeUrl,
                cookies= {self.findSessionId[0]: self.findSessionId[1]},
                callback = self.getAndHandleYzm)
        yield request

    def getAndHandleYzm(self, response):
        yzm = handle(response.body)

        yield FormRequest(self.postUrl,
                formdata={'Sel_XNXQ': '20151',
                          'sel_zc': '011',
                          'txt_yzm': yzm,
                          'type': '2'},
                headers={
                    'Referer': 'http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB.aspx',
                    'Cookie': self.findSessionId[0] + '=' + self.findSessionId[1],
                    },


                callback=self.parse)

    def parse(self, response):
        body = response.body.decode('gbk')
        num = body.find('alert')
        if num != -1:
            # means CAPTCHA validation fails, need to re-request the CAPTCHA
            yield scrapy.Request(self.vcodeUrl+'?t='+'%.f' % (datetime.now().microsecond / 1000),
            headers={
                    'Referer': 'http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB.aspx',
                    'Cookie': self.findSessionId[0]+'='+self.findSessionId[1]
                    },
            callback=self.getAndHandleYzm)

        else:
            # parse data
            self.parseData(body)
#            item = containItem()
#            item['first'] = len(body)
#            return item

    # the parse data part is a little bit long, but it doesn't matter.
    # At the last line, I did yield a item
    def parseData(self, body):
        # parse body data
        sel = Selector(text=body)

        # get all the note text data
        noteTables = sel.xpath('//table[@style="border:0px;"]').extract()

        noteList = [] # to store all the note text
        for noteTable in noteTables:
            if '<b>'  in noteTable:
                sele = Selector(text = noteTable)
                note = (sele.xpath('//table/tr/td/b/text()').extract())
                noteText = (sele.xpath('//table/tr/td/text()').extract())
                # combine note and noteText
                if not noteText:
                    noteText.append('')
                    noteText.append('')
                else:
                    if len(noteText) == 1:
                        noteText.append('')
                noteList.append(noteText)


        # get all the course data
        courseTables = sel.xpath('//table[@class="page_table"]/tbody').extract()

        AllDetailCourse = [] # all the teachers' course
        for table in courseTables:
            everyTeacherC = [] # every teacher's course
            s = Selector(text = table)
            trs = s.xpath('//tr').extract()
            for tr in trs:
                sel = Selector(text = tr)
                snum = (sel.xpath('//td[1]/text()').extract())
                course = (sel.xpath('//td[2]/text()').extract())
                credit = (sel.xpath('//td[3]/text()').extract())
                teachWay = (sel.xpath('//td[4]/text()').extract())
                courseType = (sel.xpath('//td[5]/text()').extract())
                classNum = (sel.xpath('//td[6]/text()').extract())
                className = (sel.xpath('//td[7]/text()').extract())
                stuNum = (sel.xpath('//td[8]/text()').extract())
                week = (sel.xpath('//td[9]/text()').extract())
                section = (sel.xpath('//td[10]/text()').extract())
                location = (sel.xpath('//td[11]/text()').extract())

                tmpList = []
                tmpList.append(snum)
                tmpList.append(course)
                tmpList.append(credit)
                tmpList.append(teachWay)
                tmpList.append(courseType)
                tmpList.append(classNum)
                tmpList.append(className)
                tmpList.append(stuNum)
                tmpList.append(week)
                tmpList.append(section)
                tmpList.append(location)

                # to know whether every variable is empty
                detailCourse = []
                for each in tmpList:
                    if not each:
                        each = ''
                    else:
                        each = each[0]
                    detailCourse.append(each)

                everyTeacherC.append(detailCourse)

            AllDetailCourse.append(everyTeacherC)

        # get department, teacher, gender and title
        sel = Selector(text = body)
        temp1 = sel.xpath('//*[@group="group"]/table/tr/td/text()').extract() 


        # fill two tables, which will store in the database
        i = 0
        # every professor
        for each in temp1:
            tables = containItem() # all the data in every for loop to send to the pipeline 

            each = each.replace(u'\xa0', u'  ')
            each = each.split('   ')
            depart = each[0].split('£º')
            teacher = each[1].split('£º')
            gender = each[2].split('£º')
            title = each[3].split('£º')

            # first table
            profItem = DetailProfItem()
            profItem['XNXQ'] = self.XNXQ
            profItem['department'] = depart[1] # department
            profItem['teacher'] = teacher[1] # teacher
            profItem['gender'] = gender[1]
            profItem['title'] = title[1]
            profItem['note1'] = noteList[i][0]
            profItem['note2'] = noteList[i][1]
            tables['first'] = profItem # add the first table

            # second table
            # every professor's courses
            profCourses = []
            for j in range(len(AllDetailCourse[i])): # how many course for every professor
                profCourseItem = DetailProfCourseItem() # every course for every professor
                profCourseItem['snum'] = AllDetailCourse[i][j][0] # i means i-th professor, j means j-th course, third num means what position of the course
                profCourseItem['course'] = AllDetailCourse[i][j][1]
                profCourseItem['credit'] = AllDetailCourse[i][j][2]
                profCourseItem['teachWay'] = AllDetailCourse[i][j][3]
                profCourseItem['courseType'] = AllDetailCourse[i][j][4]
                profCourseItem['classNum'] = AllDetailCourse[i][j][5]
                profCourseItem['className'] = AllDetailCourse[i][j][6]
                profCourseItem['stuNum'] = AllDetailCourse[i][j][7]
                profCourseItem['week'] = AllDetailCourse[i][j][8]
                profCourseItem['section'] = AllDetailCourse[i][j][9]
                profCourseItem['location'] = AllDetailCourse[i][j][10]
                profCourses.append(profCourseItem) # every professor's courses

            tables['second'] = profCourseItem # add the second table

            i += 1
            yield tables

Any suggestions would be appreciate!

settings.py: (pipeline part)

# Configure item pipelines
# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES = {
    'teacherCourse.pipelines.TeacherCoursePipeline': 300,
}

items.py: (I don't think it's matter)

 # detail professor course message
 class DetailProfCourseItem(scrapy.Item):
      snum = scrapy.Field() # serial number
      course = scrapy.Field() 
      credit = scrapy.Field() 
      teachWay = scrapy.Field() 
      courseType = scrapy.Field() 
      classNum = scrapy.Field() 
      className = scrapy.Field() 
      stuNum = scrapy.Field() 
      week = scrapy.Field() 
      section = scrapy.Field() 
      location = scrapy.Field() 

  # the third item which contain first and second item
  class containItem(scrapy.Item):
      first = scrapy.Field() # for fist table
      second = scrapy.Field() # for second table

pipeline code:

class TeacherCoursePipeline(object):
    def process_item(self, item, spider):
        print('I am called!!!!!')
        print(item)
        return item

And When I run spider scrapy crawl TeacherCourse

it output:

2016-07-19 17:39:18 [scrapy] INFO: Scrapy 1.1.0rc1 started (bot: teacherCourse)
2016-07-19 17:39:18 [scrapy] INFO: Overridden settings: {'BOT_NAME': 'teacherCourse', 'NEWSPIDER_MODULE': 'teacherCourse.spiders', 'ROBOTSTXT_OBEY': True, 'SPIDER_MODULES': ['teacherCourse.spiders']}
2016-07-19 17:39:18 [scrapy] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats', 'scrapy.extensions.logstats.LogStats']
2016-07-19 17:39:18 [scrapy] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.chunked.ChunkedTransferMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2016-07-19 17:39:18 [scrapy] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2016-07-19 17:39:18 [scrapy] INFO: Enabled item pipelines:
['teacherCourse.pipelines.TeacherCoursePipeline']
2016-07-19 17:39:18 [scrapy] INFO: Spider opened
2016-07-19 17:39:18 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2016-07-19 17:39:18 [scrapy] DEBUG: Crawled (404) <GET http://jwxt.dgut.edu.cn/robots.txt> (referer: None)
2016-07-19 17:39:18 [scrapy] DEBUG: Crawled (200) <GET http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB.aspx> (referer: None)
2016-07-19 17:39:19 [scrapy] DEBUG: Crawled (200) <GET http://jwxt.dgut.edu.cn/jwweb/sys/ValidateCode.aspx> (referer: http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB.aspx)
2016-07-19 17:39:19 [scrapy] DEBUG: Crawled (200) <POST http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB_rpt.aspx> (referer: http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB.aspx)
2016-07-19 17:39:19 [scrapy] INFO: Closing spider (finished)
2016-07-19 17:39:19 [scrapy] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 1330,
 'downloader/request_count': 4,
 'downloader/request_method_count/GET': 3,
 'downloader/request_method_count/POST': 1,
 'downloader/response_bytes': 230886,
 'downloader/response_count': 4,
 'downloader/response_status_count/200': 3,
 'downloader/response_status_count/404': 1,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2016, 7, 19, 9, 39, 19, 861620),
 'log_count/DEBUG': 4,
 'log_count/INFO': 7,
 'request_depth_max': 2,
 'response_received_count': 4,
 'scheduler/dequeued': 3,
 'scheduler/dequeued/memory': 3,
 'scheduler/enqueued': 3,
 'scheduler/enqueued/memory': 3,
 'start_time': datetime.datetime(2016, 7, 19, 9, 39, 18, 774293)}
2016-07-19 17:39:19 [scrapy] INFO: Spider closed (finished)

回答1:

The problem seems to be that the parse method only yields scrapy.Request objects, never scrapy.Item instances.

The else: branch calls the generator parseData(body) but doesn't use the data it can produce (namely containItem objects).

One way to solve this is to loop on the generator results and yield them one-by-one:

    def parse(self, response):
        body = response.body.decode('gbk')
        num = body.find('alert')
        if num != -1:
            # means CAPTCHA validation fails, need to re-request the CAPTCHA
            yield scrapy.Request(self.vcodeUrl+'?t='+'%.f' % (datetime.now().microsecond / 1000),
            headers={
                    'Referer': 'http://jwxt.dgut.edu.cn/jwweb/ZNPK/TeacherKBFB.aspx',
                    'Cookie': self.findSessionId[0]+'='+self.findSessionId[1]
                    },
            callback=self.getAndHandleYzm)

        else:
            # parse data
            for i in self.parseData(body):
                yield i

#            item = containItem()
#            item['first'] = len(body)
#            return item