I am VERY new to python and scrapy. I wrote a working script with the use of scrapy and need a little improvement to avoid redundancies.
At the parse_article_page function I came across 2 possibilities. Either the article has variants (more pages to scrap) or not. Can you help me to avoid the double use of the code in the else-statement and parse_data function?
I tried a second request, but this seems not to work. Log says "DEBUG: Filtered duplicate request" or it says nothing.
def parse_article_page(self, response):
#Check for variants
variants = response.xpath('//div[#class="variants"]/select/option[not(#disabled)]/#variant_href').extract()
if len(variants) > 1:
for variant in variants:
variant_url = response.urljoin(variant)
#Request article variants:
yield scrapy.Request(variant_url, callback=self.parse_data)
else:
#yield scrapy.Request(response.url, callback=self.parse_data) #Does not work
item = ShopItem()
item['desc'] = response.css(description_selector).extract()
item['price'] = response.css(price_selector).extract()
item['itno'] = response.css(no_selector).extract()
item['url'] = response.url
yield item
def parse_data(self, response):
item = ShopItem()
item['desc'] = response.css(description_selector).extract()
item['price'] = response.css(price_selector).extract()
item['itno'] = response.css(no_selector).extract()
item['url'] = response.url
yield item
calling else: self.parse_data(response) won't work because you still need to yield the item inside that method for scrapy to get it, You'll have to do something like this:
def parse_article_page(self, response):
#Check for variants
variants = response.xpath('//div[#class="variants"]/select/option[not(#disabled)]/#variant_href').extract()
if len(variants) > 1:
for variant in variants:
variant_url = response.urljoin(variant)
#Request article variants:
yield scrapy.Request(variant_url, callback=self.parse_data)
else:
for item in self.parse_data(response):
yield item
def parse_data(self, response):
item = ShopItem()
item['desc'] = response.css(description_selector).extract()
item['price'] = response.css(price_selector).extract()
item['itno'] = response.css(no_selector).extract()
item['url'] = response.url
yield item
Related
def parse(self, response):
category_names = []
category_urls = []
for item in response.css("#zg_browseRoot ul li"):
category_url = item.css("a").css(self.CSS_URL).extract()
category_name = item.css("a").css(self.CSS_TEXT).extract()
category_url = [
self.parse_url(category_url, 4) for category_url in category_url
]
(category_url,) = category_url
(category_name,) = category_name
category_names.append(category_name)
category_urls.append(category_url)
for c_name, url in zip(category_names, category_urls):
self.c_name = [c_name]
yield scrapy.Request(url, callback=self.parse_categories)
def parse_url(self, url, number):
parse = urlparse(url)
split = parse.path.split("/")[:number]
return f'{self.BASE_URL}{"/".join(split)}'
def parse_categories(self, response):
sub_names = []
sub_urls = []
for item in response.css("#zg_browseRoot ul ul li"):
sub_name = item.css("a").css(self.CSS_TEXT).extract()
sub_url = item.css("a").css(self.CSS_URL).extract()
sub_url = [self.parse_url(sub_url, 5) for sub_url in sub_url]
(sub_url,) = sub_url
(sub_name,) = sub_name
sub_names.append(sub_name)
sub_urls.append(sub_url)
for sub_name, url in zip(sub_names, sub_urls):
self.sub_name = [sub_name]
# print("{}: {}, {}".format(url, self.sub_name, self.c_name))
yield scrapy.Request(url, callback=self.parse_subcategories)
def parse_subcategories(self, response):
url = self.parse_url(response.request.url, 5)
print(f"{self.c_name}, {self.sub_name}, {url}")
Hello everyone,
I'm having an issue with my Scrapy approach. I'm trying to scrape page which has categories and subcategories in which are items. I want to include category and subcategory with each item scraped.
The problem is that the Scrapys callback function is asynchronous and zipping the URLs with names doesn't seem to work, because the for loop is processed first, URLs are stored in a generator and names are staying behind. Can anyone help me to work around this?
Thanks in advance,
Daniel.
You can pass arbitrary data along with the requests by using th cb_kwargs parameter. You can read about the details here.
Here is a simplified example:
def parse(self, response):
rows = response.xpath('//div[#id="some-element"]')
for row in rows:
request_url = row.xpath('a/#href').get()
category = row.xpath('a/text()').get()
yield Request(
url=request_url,
callback=self.parse_category,
cb_kwargs={'category': category}
)
def parse_category(self, response, category): # Notice category arg in the func
# Process here
yield item
The data inserted in cb_kwargs is passed as a keyword arg into the callback function, so the key in the dict must match the name of the argument in the method definiton.
cb_kwargs were introduced in Scrapy v1.7, if you are using an older version you should use the meta param. You can read about it here, notice that the use is slightly different.
My spide looks like this/;
class ScrapeMovies(scrapy.Spider):
start_urls = [
'https://www.trekearth.com/members/page1.htm?sort_by=md'
]
def parse(self, response):
for row in response.xpath('//table[#class="member-table"]//tr[position() > 1]'):
item = loopitem()
website = row.xpath('./td[2]//a/#href/text()').extract_first()
item['name'] = row.xpath('./td[2]//a/text()').extract_first()
yield item
# This part is responsible for scraping all of the pages on a start url commented out for convinience
# next_page=response.xpath('//div[#class="page-nav-btm"]/ul/li[last()]/a/#href').extract_first()
# if next_page is not None:
# next_page=response.urljoin(next_page)
# yield scrapy.Request(next_page, callback=self.parse)
What it does as of know it scrapes the table (see the starting url). I want it to then go the link (members name column) and then extract some informations from this link (link is e.g. https://www.trekearth.com/members/monareng/) and the return this as an item.
How should i approach this?
If anything is unclear please do not hesitate to ask for clarification.
EDIT:
nowy my code looks as follows (however still does not work):
class ScrapeMovies(scrapy.Spider):
name='final'
start_urls = [
'https://www.trekearth.com/members/page1.htm?sort_by=md'
]
def parse(self, response):
for row in response.xpath('//table[#class="member-table"]//tr[position() > 1]'):
item = FinalItem()
website = row.xpath('./td[2]//a/#href/text()').extract_first()
item['name'] = row.xpath('./td[2]//a/text()').extract_first()
request = scrapy.Request(website,
callback=self.parse_page2)
request.meta['item'] = item
return request
def parse_page2(self, response):
item = response.meta['item']
item['other_url'] = response.url
item['groups'] = response.xpath('//div[#class="groups-btm"]/ul/li/text()').extract_first()
return item
Use meta field to put item forward to next callback
def parse_page1(self, response):
item = MyItem(main_url=response.url)
request = scrapy.Request("http://www.example.com/some_page.html",
callback=self.parse_page2)
request.meta['item'] = item
return request
def parse_page2(self, response):
item = response.meta['item']
item['other_url'] = response.url
return item
UPD: to process all rows use a yield in your loop
for row in response.xpath('//table[#class="member-table"]//tr[position() > 1]'):
item = FinalItem()
website = row.xpath('./td[2]//a/#href/text()').extract_first()
item['name'] = row.xpath('./td[2]//a/text()').extract_first()
request = scrapy.Request(website,
callback=self.parse_page2)
request.meta['item'] = item
yield request
I am trying to scrape a website using Scrapy. Example Link is: Here.
I am able to get some data using css selectors. I also need to fetch all image urls of each item. Now an item can have multiple colours. When we click on another colour, it actually fetch images from another url in the browser. So, I need to generate manual requests (due to multiple colours) and attach "meta" to store image urls from others urls into a SINGLE ITEM FIELD.
Here is my Scrapy code:
def get_image_urls(self, response):
item = response.meta['item']
if 'image_urls' in item:
urls = item['image_urls']
else:
urls = []
urls.extend(response.css('.product-image-link::attr(href)').extract())
item['image_urls'] = urls
next_url = response.css('.va-color .emptyswatch a::attr(href)').extract()
#print(item['image_urls'])
yield Request(next_url[0], callback=self.get_image_urls, meta={'item': item})
def parse(self, response):
output = JulesProduct()
output['name'] = self.get_name(response)
# Now get the recursive img urls
response.meta['item'] = output
self.get_image_urls(response)
return output
Ideally, I should return output object to have all of the required data. My question is why I am not getting output['image_urls']? Because when I uncomment print statement in get_image_urls function, I see 3 crawled urls and 3 print statements with url appended after each other. I need them in the parse function. I'm not sure if I'm able to dictate my issue. Can anybody help?
Your parse method is returning the output before the get_image_urls requests are done.
You should only yield or return your final item and at the end of your recursive logic. Something like this should work:
def parse(self, response):
output = JulesProduct()
output['name'] = self.get_name(response)
yield Request(response.url, callback=self.get_image_urls, meta={'item': item}, dont_filter=True)
def get_image_urls(self, response):
item = response.meta['item']
if 'image_urls' in item:
urls = item['image_urls']
else:
urls = []
urls.extend(response.css('.product-image-link::attr(href)').extract())
item['image_urls'] = urls
next_url = response.css('.va-color .emptyswatch a::attr(href)').extract()
if len(next_url) > 0:
yield Request(next_url[0], callback=self.get_image_urls, meta={'item': item})
else:
yield item
I'm using scrapy for scraping some pages and I want in each row:
Title
Url
Author
The problem is that (sometimes) there are more titles and urls but the author comes just one time in each page. So I want to add the respective author to urls and titles (which come out fine).
This is my (bad) code, I tried to make a loop but it doesn't work very well I think, plus, it raises me the error "Spider must return Request, BaseItem, dict or None, got 'list'". Can you tell me where is my mistake?
def parse(self, response):
sels = response.xpath('//td[#class="default"]')
items = []
for sel in sels:
item = ThisItem()
item['URL'] = sel.xpath('//td[#class]/a/#href').extract()
item['TITLE'] = sel.xpath('//td[#class]/a').extract()
i = item['TITLE']
for i in sels:
item['AUTHOR'] = sel.xpath('//td[#class]/b[1]').extract()
items.append(item)
yield items
Thanks in advance.
You should yield every item separately. Try this
def parse(self, response):
author = response.xpath('//td[#class]/b[1]').extract()
for sel in response.xpath('//td[#class="default"]'):
item = ThisItem()
item['URL'] = sel.xpath('//td[#class]/a/#href').extract()
item['TITLE'] = sel.xpath('//td[#class]/a').extract()
item['AUTHOR'] = author
yield item
I am building a simple(ish) parser in Scrapy and I am blissfully ignorant when it comes to scrapy and Python :-) In the file item.py I have a definition of thisItem() which I assign to item in the code below. All worked rather swimmingly, parseusing a callback to get to parse_dir_content... But then I realized I needed to scrape an extra bit of data and created another function parse_other_content. How do I get what is already in item into parse_other_content?
import scrapy
from this-site.items import *
import re
import json
class DmozSpider(scrapy.Spider):
name = "ABB"
allowed_domains = ["this-site.com.au"]
start_urls = [
"https://www.this-site.com.au?page=1",
"https://www.this-site.com.au?page=2",
]
def parse(self, response):
for href in response.xpath('//h3/a/#href'):
url = response.urljoin(href.extract())
yield scrapy.Request(url, callback=self.parse_dir_contents)
def parse_dir_contents(self, response):
for sel in response.xpath('//h1[#itemprop="name"]'):
item = thisItem()
item['title'] = sel.xpath('text()').extract()
item['rate'] = response.xpath('//div[#class="rate"]/div/span/text()').extract()
so = re.search( r'\d+', response.url)
propID = so.group()
item['propid'] = propID
item['link'] = response.url
yield scrapy.Request("https://www.this-site.com.au/something?listing_id="+propID,callback=self.parse_other_content)
#yield item
def parse_other_content(self, reponse):
sel = json.loads(reponse.body)
item['rate_detail'] = sel["this"][0]["that"]
yield item
I know I am missing something simple here, but I can't seem to figure it out.
Per the scrapy documentation (http://doc.scrapy.org/en/1.0/topics/request-response.html#topics-request-response-ref-request-callback-arguments):
In some cases you may be interested in passing arguments to those callback functions so you can receive the arguments later, in the second callback. You can use the Request.meta attribute for that.
In your case I would do something like this:
def parse_dir_contents(self, response):
for sel in response.xpath('//h1[#itemprop="name"]'):
item = thisItem()
...
request = scrapy.Request("https://www.this-site.com.au/something?listing_id="+propID,callback=self.parse_other_content)
request.meta['item'] = item
yield request
def parse_other_content(self, response):
item = response.meta['item']
# do something with the item
return item
According to Steve (see comments) you can also pass a dictionary of meta data as a keyword argument to the Request constructor like so:
def parse_dir_contents(self, response):
for sel in response.xpath('//h1[#itemprop="name"]'):
item = thisItem()
...
request = scrapy.Request("https://www.this-site.com.au/something?listing_id="+propID,callback=self.parse_other_content, meta={'item':item})
yield request
You can either allow item to be visible to parse_other_content() by changing it to self.item, or sending it as a parameter to the function. (The first one might be easier.)
For the first solution just add self. to any reference to the item variable. This makes it visible to the entire class.
def parse_dir_contents(self, response):
for sel in response.xpath('//h1[#itemprop="name"]'):
self.item = thisItem()
self.item['title'] = sel.xpath('text()').extract()
self.item['rate'] = response.xpath('//div[#class="rate"]/div/span/text()').extract()
so = re.search( r'\d+', response.url)
propID = so.group()
self.item['propid'] = propID
self.item['link'] = response.url
yield scrapy.Request("https://www.this-site.com.au/something?listing_id="+propID,callback=self.parse_other_content)
#yield item
def parse_other_content(self, reponse):
sel = json.loads(reponse.body)
self.item['rate_detail'] = sel["this"][0]["that"]
yield self.item