Debugging Tracebacks in Python/Scrapy

Question

I need help with a tracback error I'm getting. Some context, I have a scrapy spider that's obviously getting some processing errors, It's meant to scrap a website and store the URL, Date and Title in a mongodb. I'm not sure where to even start debugging here. Here are the errors;

    2016-02-19 18:34:47 [scrapy] DEBUG: Crawled (200) <GET http://www.stuff.co.nz/business/farming/77040713/farmer-thomas-king-loses-supreme-court-case-over-farm-eviction> (referer: http://www.stuff.co.nz/business/)
2016-02-19 18:34:47 [scrapy] ERROR: Error processing {'date': 'Thu Feb 18 19:49:51 UTC 2016',
 'title': 'Farmer loses eviction case',
 'url': 'http://www.stuff.co.nz/business/farming/77040713/farmer-thomas-king-loses-supreme-court-case-over-farm-eviction'}
Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/twisted/internet/defer.py", line 588, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/usr/lib/python2.7/site-packages/scrapy_mongodb.py", line 222, in process_item
    return self.insert_item(item, spider)
  File "/usr/lib/python2.7/site-packages/scrapy_mongodb.py", line 251, in insert_item
    self.collection.insert(item, continue_on_error=True)
  File "/usr/lib64/python2.7/site-packages/pymongo/collection.py", line 1926, in insert
    check_keys, manipulate, write_concern)
  File "/usr/lib64/python2.7/site-packages/pymongo/collection.py", line 430, in _insert
    gen(), check_keys, self.codec_options, sock_info)
  File "/usr/lib64/python2.7/site-packages/pymongo/pool.py", line 254, in write_command
    helpers._check_command_response(result)
  File "/usr/lib64/python2.7/site-packages/pymongo/helpers.py", line 188, in _check_command_response
    raise OperationFailure(msg % errmsg, code, response)
OperationFailure: not authorized on article to execute command { insert: "stuffconz", ordered: false, writeConcern: { fsync: false }, documents: [ { _id: ObjectId('56c6a97702f22371605f4668'), url: "http://www.stuff.co.nz/business/farming/77040713/farmer-thomas-king-loses-supreme-court-case-over-farm-eviction", date: "Thu Feb 18 19:49:51 UTC 2016", title: "Farmer loses eviction case" } ] }

Here's the scrapy spider;

    from __future__ import absolute_import

from scrapy import Spider
from scrapy.selector import Selector
from scrapy.http import Request
from scrapy.linkextractors import LinkExtractor
from harland.items import *
from scrapy.spiders import CrawlSpider, Rule

class StuffSpider(CrawlSpider):
    name = "stuff"
    allowed_domains = ["stuff.co.nz"]
    start_urls = [
        "http://stuff.co.nz/business/",
    ]

    rules = (
        Rule(LinkExtractor(allow=".*/business.*"), callback='parse_article_page', follow=True),
    )

    def parse_article_page(self, response):

        article = Selector(response)
        page = Selector(response).xpath('/html/head/meta[9]')
        page_type = page.xpath('//meta[@property="og:type"]/@content').extract()[0]

        if "article" in page_type:
          item = StuffItem()

          item_url = page.xpath('//meta[@property="og:url"]/@content').extract()[0]
          item['url'] = str(item_url)
          item_title = page.xpath('//meta[@property="og:title"]/@content').extract()[0]
          item['title'] = str(item_title)
          item_date = page.xpath('//*[@itemprop="datePublished"]/@content').extract()[0]
          item['date'] = str(item_date)
          yield item

And here's the Pipeline, taken directly from here: https://github.com/sebdah/scrapy-mongodb/blob/master/scrapy_mongodb.py

"""
scrapy-mongodb - MongoDB pipeline for Scrapy
Homepage: https://github.com/sebdah/scrapy-mongodb
Author: Sebastian Dahlgren <sebastian.dahlgren@gmail.com>
License: Apache License 2.0 <http://www.apache.org/licenses/LICENSE-2.0.html>
Copyright 2013 Sebastian Dahlgren
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
   http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
import datetime

from pymongo import errors
from pymongo.mongo_client import MongoClient
from pymongo.mongo_replica_set_client import MongoReplicaSetClient
from pymongo.read_preferences import ReadPreference

from scrapy import log
from scrapy.contrib.exporter import BaseItemExporter

VERSION = '0.9.1'


def not_set(string):
    """ Check if a string is None or ''
    :returns: bool - True if the string is empty
    """
    if string is None:
        return True
    elif string == '':
        return True
    return False


class MongoDBPipeline(BaseItemExporter):
    """ MongoDB pipeline class """
    # Default options
    config = {
        'uri': 'mongodb://harland:Ase0peedi@localhost:27017',
        'fsync': False,
        'write_concern': 0,
        'database': 'article',
        'collection': 'stuffconz',
        'replica_set': None,
        'unique_key': None,
        'buffer': None,
        'append_timestamp': True,
        'stop_on_duplicate': 0,
    }

    # Item buffer
    current_item = 0
    item_buffer = []

    # Duplicate key occurence count
    duplicate_key_count = 0

    def load_spider(self, spider):
        self.crawler = spider.crawler
        self.settings = spider.settings

        # Versions prior to 0.25
        if not hasattr(spider, 'update_settings') and hasattr(spider, 'custom_settings'):
            self.settings.setdict(spider.custom_settings or {}, priority='project')

    def open_spider(self, spider):
        self.load_spider(spider)

        # Configure the connection
        self.configure()

        if self.config['replica_set'] is not None:
            connection = MongoReplicaSetClient(
                self.config['uri'],
                replicaSet=self.config['replica_set'],
                w=self.config['write_concern'],
                fsync=self.config['fsync'],
                read_preference=ReadPreference.PRIMARY_PREFERRED)
        else:
            # Connecting to a stand alone MongoDB
            connection = MongoClient(
                self.config['uri'],
                fsync=self.config['fsync'],
                read_preference=ReadPreference.PRIMARY)

        # Set up the collection
        database = connection[self.config['database']]
        self.collection = database[self.config['collection']]
        log.msg(u'Connected to MongoDB {0}, using "{1}/{2}"'.format(
            self.config['uri'],
            self.config['database'],
            self.config['collection']))

        # Ensure unique index
        if self.config['unique_key']:
            self.collection.ensure_index(self.config['unique_key'], unique=True)
            log.msg(u'Ensuring index for key {0}'.format(
                self.config['unique_key']))

        # Get the duplicate on key option
        if self.config['stop_on_duplicate']:
            tmpValue = self.config['stop_on_duplicate']
            if tmpValue < 0:
                log.msg(
                    (
                        u'Negative values are not allowed for'
                        u' MONGODB_STOP_ON_DUPLICATE option.'
                    ),
                    level=log.ERROR
                )
                raise SyntaxError(
                    (
                        'Negative values are not allowed for'
                        ' MONGODB_STOP_ON_DUPLICATE option.'
                    )
                )
            self.stop_on_duplicate = self.config['stop_on_duplicate']
        else:
            self.stop_on_duplicate = 0

    def configure(self):
        """ Configure the MongoDB connection """
        # Handle deprecated configuration
        if not not_set(self.settings['MONGODB_HOST']):
            log.msg(
                u'DeprecationWarning: MONGODB_HOST is deprecated',
                level=log.WARNING)
            mongodb_host = self.settings['MONGODB_HOST']

            if not not_set(self.settings['MONGODB_PORT']):
                log.msg(
                    u'DeprecationWarning: MONGODB_PORT is deprecated',
                    level=log.WARNING)
                self.config['uri'] = 'mongodb://{0}:{1:i}'.format(
                    mongodb_host,
                    self.settings['MONGODB_PORT'])
            else:
                self.config['uri'] = 'mongodb://{0}:27017'.format(mongodb_host)

        if not not_set(self.settings['MONGODB_REPLICA_SET']):
            if not not_set(self.settings['MONGODB_REPLICA_SET_HOSTS']):
                log.msg(
                    (
                        u'DeprecationWarning: '
                        u'MONGODB_REPLICA_SET_HOSTS is deprecated'
                    ),
                    level=log.WARNING)
                self.config['uri'] = 'mongodb://{0}'.format(
                    self.settings['MONGODB_REPLICA_SET_HOSTS'])

        # Set all regular options
        options = [
            ('uri', 'MONGODB_URI'),
            ('fsync', 'MONGODB_FSYNC'),
            ('write_concern', 'MONGODB_REPLICA_SET_W'),
            ('database', 'MONGODB_DATABASE'),
            ('collection', 'MONGODB_COLLECTION'),
            ('replica_set', 'MONGODB_REPLICA_SET'),
            ('unique_key', 'MONGODB_UNIQUE_KEY'),
            ('buffer', 'MONGODB_BUFFER_DATA'),
            ('append_timestamp', 'MONGODB_ADD_TIMESTAMP'),
            ('stop_on_duplicate', 'MONGODB_STOP_ON_DUPLICATE')
        ]

        for key, setting in options:
            if not not_set(self.settings[setting]):
                self.config[key] = self.settings[setting]

        # Check for illegal configuration
        if self.config['buffer'] and self.config['unique_key']:
            log.msg(
                (
                    u'IllegalConfig: Settings both MONGODB_BUFFER_DATA '
                    u'and MONGODB_UNIQUE_KEY is not supported'
                ),
                level=log.ERROR)
            raise SyntaxError(
                (
                    u'IllegalConfig: Settings both MONGODB_BUFFER_DATA '
                    u'and MONGODB_UNIQUE_KEY is not supported'
                ))

    def process_item(self, item, spider):
        """ Process the item and add it to MongoDB
        :type item: Item object
        :param item: The item to put into MongoDB
        :type spider: BaseSpider object
        :param spider: The spider running the queries
        :returns: Item object
        """
        item = dict(self._get_serialized_fields(item))

        if self.config['buffer']:
            self.current_item += 1

            if self.config['append_timestamp']:
                item['scrapy-mongodb'] = {'ts': datetime.datetime.utcnow()}

            self.item_buffer.append(item)

            if self.current_item == self.config['buffer']:
                self.current_item = 0
                return self.insert_item(self.item_buffer, spider)

            else:
                return item

        return self.insert_item(item, spider)

    def close_spider(self, spider):
        """ Method called when the spider is closed
        :type spider: BaseSpider object
        :param spider: The spider running the queries
        :returns: None
        """
        if self.item_buffer:
            self.insert_item(self.item_buffer, spider)

    def insert_item(self, item, spider):
        """ Process the item and add it to MongoDB
        :type item: (Item object) or [(Item object)]
        :param item: The item(s) to put into MongoDB
        :type spider: BaseSpider object
        :param spider: The spider running the queries
        :returns: Item object
        """
        if not isinstance(item, list):
            item = dict(item)

            if self.config['append_timestamp']:
                item['scrapy-mongodb'] = {'ts': datetime.datetime.utcnow()}

        if self.config['unique_key'] is None:
            try:
                self.collection.insert(item, continue_on_error=True)
                log.msg(
                    u'Stored item(s) in MongoDB {0}/{1}'.format(
                        self.config['database'], self.config['collection']),
                    level=log.DEBUG,
                    spider=spider)
            except errors.DuplicateKeyError:
                log.msg(u'Duplicate key found', level=log.DEBUG)
                if (self.stop_on_duplicate > 0):
                    self.duplicate_key_count += 1
                    if (self.duplicate_key_count >= self.stop_on_duplicate):
                        self.crawler.engine.close_spider(
                            spider,
                            'Number of duplicate key insertion exceeded'
                        )
                pass

        else:
            key = {}
            if isinstance(self.config['unique_key'], list):
                for k in dict(self.config['unique_key']).keys():
                    key[k] = item[k]
            else:
                key[self.config['unique_key']] = item[self.config['unique_key']]

            self.collection.update(key, item, upsert=True)

            log.msg(
                u'Stored item(s) in MongoDB {0}/{1}'.format(
                    self.config['database'], self.config['collection']),
                level=log.DEBUG,
                spider=spider)

        return item

If someone can just point me in the right direction that would be so helpful! I've been playing around for days, but I'm beginning to think I just don't know enough about Python and scrapy yet.

Cheers,

Answer 1

Before executing this method 'parse_article_page', you need to login to the website using scrapy method to scrap data from the website.

Error clearly says : "OperationFailure: not authorized on article to execute command", that you are not authorized to execute command.

class MySpider(scrapy.Spider):
    name = 'myspider'
    def start_requests(self):
        return [scrapy.FormRequest("http://www.example.com/login",
          formdata={'user': 'john', 'pass': 'secret'},
          callback=self.logged_in)]
    def logged_in(self, response):
        # here you would extract links to follow and return Requests for
        # each of them, with another callback
        pass