scrapy custom output processor












1















I'm using the scrapy framework for a web scraping project but I can't seem to figure out how to get a custom output processor to work.



I have an item class like so:



class Item(scrapy.Item)

ad_type = scrapy.Field()


then my parse function looks something like this. I have 2 scraped strings which I am adding to the ad_type. I want my output processor function to assign tags based on what is scraped from these 2 xpaths.



def parse(self, response):

l = ItemLoader(item=Item(), selector=listing)
l.add_xpath('ad_type', '(.//div/@class)[1]')
l.add_xpath('ad_type', '(.//div[contains(@class, "brand")]/@class)[1]')
yield l.load_item()


How do I get my output processor function to access the 2 xpath scraped strings that I have added to ad_type? The scrapy docs give this example but I can't get it to work.



def lowercase_processor(self, values):
for v in values:
yield v.lower()

class MyItemLoader(ItemLoader):
name_in = lowercase_processor









share|improve this question



























    1















    I'm using the scrapy framework for a web scraping project but I can't seem to figure out how to get a custom output processor to work.



    I have an item class like so:



    class Item(scrapy.Item)

    ad_type = scrapy.Field()


    then my parse function looks something like this. I have 2 scraped strings which I am adding to the ad_type. I want my output processor function to assign tags based on what is scraped from these 2 xpaths.



    def parse(self, response):

    l = ItemLoader(item=Item(), selector=listing)
    l.add_xpath('ad_type', '(.//div/@class)[1]')
    l.add_xpath('ad_type', '(.//div[contains(@class, "brand")]/@class)[1]')
    yield l.load_item()


    How do I get my output processor function to access the 2 xpath scraped strings that I have added to ad_type? The scrapy docs give this example but I can't get it to work.



    def lowercase_processor(self, values):
    for v in values:
    yield v.lower()

    class MyItemLoader(ItemLoader):
    name_in = lowercase_processor









    share|improve this question

























      1












      1








      1








      I'm using the scrapy framework for a web scraping project but I can't seem to figure out how to get a custom output processor to work.



      I have an item class like so:



      class Item(scrapy.Item)

      ad_type = scrapy.Field()


      then my parse function looks something like this. I have 2 scraped strings which I am adding to the ad_type. I want my output processor function to assign tags based on what is scraped from these 2 xpaths.



      def parse(self, response):

      l = ItemLoader(item=Item(), selector=listing)
      l.add_xpath('ad_type', '(.//div/@class)[1]')
      l.add_xpath('ad_type', '(.//div[contains(@class, "brand")]/@class)[1]')
      yield l.load_item()


      How do I get my output processor function to access the 2 xpath scraped strings that I have added to ad_type? The scrapy docs give this example but I can't get it to work.



      def lowercase_processor(self, values):
      for v in values:
      yield v.lower()

      class MyItemLoader(ItemLoader):
      name_in = lowercase_processor









      share|improve this question














      I'm using the scrapy framework for a web scraping project but I can't seem to figure out how to get a custom output processor to work.



      I have an item class like so:



      class Item(scrapy.Item)

      ad_type = scrapy.Field()


      then my parse function looks something like this. I have 2 scraped strings which I am adding to the ad_type. I want my output processor function to assign tags based on what is scraped from these 2 xpaths.



      def parse(self, response):

      l = ItemLoader(item=Item(), selector=listing)
      l.add_xpath('ad_type', '(.//div/@class)[1]')
      l.add_xpath('ad_type', '(.//div[contains(@class, "brand")]/@class)[1]')
      yield l.load_item()


      How do I get my output processor function to access the 2 xpath scraped strings that I have added to ad_type? The scrapy docs give this example but I can't get it to work.



      def lowercase_processor(self, values):
      for v in values:
      yield v.lower()

      class MyItemLoader(ItemLoader):
      name_in = lowercase_processor






      python scrapy






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      share|improve this question










      asked Nov 19 '18 at 23:39









      user3381431user3381431

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          You have named your loader MyItemLoader, but your spider uses ItemLoader (probably scrapy's).

          If you update your code to use the custom loader, you should get the result you want.



          I would also recommend not naming your item class Item, since that could be confusing.






          share|improve this answer
























          • Thanks that did the trick

            – user3381431
            Nov 21 '18 at 21:58











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          1 Answer
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          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          1














          You have named your loader MyItemLoader, but your spider uses ItemLoader (probably scrapy's).

          If you update your code to use the custom loader, you should get the result you want.



          I would also recommend not naming your item class Item, since that could be confusing.






          share|improve this answer
























          • Thanks that did the trick

            – user3381431
            Nov 21 '18 at 21:58
















          1














          You have named your loader MyItemLoader, but your spider uses ItemLoader (probably scrapy's).

          If you update your code to use the custom loader, you should get the result you want.



          I would also recommend not naming your item class Item, since that could be confusing.






          share|improve this answer
























          • Thanks that did the trick

            – user3381431
            Nov 21 '18 at 21:58














          1












          1








          1







          You have named your loader MyItemLoader, but your spider uses ItemLoader (probably scrapy's).

          If you update your code to use the custom loader, you should get the result you want.



          I would also recommend not naming your item class Item, since that could be confusing.






          share|improve this answer













          You have named your loader MyItemLoader, but your spider uses ItemLoader (probably scrapy's).

          If you update your code to use the custom loader, you should get the result you want.



          I would also recommend not naming your item class Item, since that could be confusing.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Nov 20 '18 at 9:03









          stranacstranac

          13.7k31724




          13.7k31724













          • Thanks that did the trick

            – user3381431
            Nov 21 '18 at 21:58



















          • Thanks that did the trick

            – user3381431
            Nov 21 '18 at 21:58

















          Thanks that did the trick

          – user3381431
          Nov 21 '18 at 21:58





          Thanks that did the trick

          – user3381431
          Nov 21 '18 at 21:58


















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