I have used the same code as in the documentation with a small difference of instantiating the Crawlrunner with settings so that it doesn't miss the pipeline operations.If this is not used it will work fine but will skip the pipeline.
from twisted.internet import reactor
import scrapy
from scrapy.crawler import CrawlerRunner
from scrapy.utils.log import configure_logging
from forspef_scrapper import ForspefScrapper
from scrapy.utils.project import get_project_settings
configure_logging({'LOG_FORMAT': '%(levelname)s: %(message)s'})
runner = CrawlerRunner(get_project_settings())
d = runner.crawl(ForspefScrapper)
d.addBoth(lambda _: reactor.stop())
reactor.run()
Please suggest the cause of this and possible fixes.
Remove the callback for reactor.stop and you should not see that issue anymore. The reactor is designed to always be running
Related
I get twisted.internet.error.ReactorNotRestartable error when I execute following code:
from time import sleep
from scrapy import signals
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from scrapy.xlib.pydispatch import dispatcher
result = None
def set_result(item):
result = item
while True:
process = CrawlerProcess(get_project_settings())
dispatcher.connect(set_result, signals.item_scraped)
process.crawl('my_spider')
process.start()
if result:
break
sleep(3)
For the first time it works, then I get error. I create process variable each time, so what's the problem?
By default, CrawlerProcess's .start() will stop the Twisted reactor it creates when all crawlers have finished.
You should call process.start(stop_after_crawl=False) if you create process in each iteration.
Another option is to handle the Twisted reactor yourself and use CrawlerRunner. The docs have an example on doing that.
I was able to solve this problem like this. process.start() should be called only once.
from time import sleep
from scrapy import signals
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from scrapy.xlib.pydispatch import dispatcher
result = None
def set_result(item):
result = item
while True:
process = CrawlerProcess(get_project_settings())
dispatcher.connect(set_result, signals.item_scraped)
process.crawl('my_spider')
process.start()
For a particular process once you call reactor.run() or process.start() you cannot rerun those commands. The reason is the reactor cannot be restarted. The reactor will stop execution once the script completes the execution.
So the best option is to use different subprocesses if you need to run the reactor multiple times.
you can add the content of while loop to a function(say execute_crawling).
Then you can simply run this using different subprocesses. For this python Process module can be used.
Code is given below.
from multiprocessing import Process
def execute_crawling():
process = CrawlerProcess(get_project_settings())#same way can be done for Crawlrunner
dispatcher.connect(set_result, signals.item_scraped)
process.crawl('my_spider')
process.start()
if __name__ == '__main__':
for k in range(Number_of_times_you_want):
p = Process(target=execute_crawling)
p.start()
p.join() # this blocks until the process terminates
Ref http://crawl.blog/scrapy-loop/
import scrapy
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from twisted.internet import reactor
from twisted.internet.task import deferLater
def sleep(self, *args, seconds):
"""Non blocking sleep callback"""
return deferLater(reactor, seconds, lambda: None)
process = CrawlerProcess(get_project_settings())
def _crawl(result, spider):
deferred = process.crawl(spider)
deferred.addCallback(lambda results: print('waiting 100 seconds before
restart...'))
deferred.addCallback(sleep, seconds=100)
deferred.addCallback(_crawl, spider)
return deferred
_crawl(None, MySpider)
process.start()
I faced error ReactorNotRestartable on AWS lambda and after I came to this solution
By default, the asynchronous nature of scrapy is not going to work well with Cloud Functions, as we'd need a way to block on the crawl to prevent the function from returning early and the instance being killed before the process terminates.
Instead, we can use `
import scrapy
import scrapy.crawler as crawler
rom scrapy.spiders import CrawlSpider
import scrapydo
scrapydo.setup()
# your spider
class QuotesSpider(scrapy.Spider):
name = "quotes"
start_urls = ['http://quotes.toscrape.com/tag/humor/']
def parse(self, response):
for quote in response.css('div.quote'):
print(quote.css('span.text::text').extract_first())
scrapydo.run_spider(QuotesSpider)
` to run your existing spider in a blocking fashion:
I was able to mitigate this problem using package crochet via this simple code based on Christian Aichinger's answer to the duplicate of this question Scrapy - Reactor not Restartable.
The initialization of Spiders is done in the main thread whereas the particular crawling is done in different thread. I'm using Anaconda (Windows).
import time
import scrapy
from scrapy.crawler import CrawlerRunner
from crochet import setup
class MySpider(scrapy.Spider):
name = "MySpider"
allowed_domains = ['httpbin.org']
start_urls = ['http://httpbin.org/ip']
def parse(self, response):
print(response.text)
for i in range(1,6):
time.sleep(1)
print("Spider "+str(self.name)+" waited "+str(i)+" seconds.")
def run_spider(number):
crawler = CrawlerRunner()
crawler.crawl(MySpider,name=str(number))
setup()
for i in range(1,6):
time.sleep(1)
print("Initialization of Spider #"+str(i))
run_spider(i)
I had a similar issue using Spyder. Running the file from the command line instead fixed it for me.
Spyder seems to work the first time but after that it doesn't. Maybe the reactor stays open and doesn't close?
I could advice you to run scrapers using subprocess module
from subprocess import Popen, PIPE
spider = Popen(["scrapy", "crawl", "spider_name", "-a", "argument=value"], stdout=PIPE)
spider.wait()
If you're trying to get a flask or django or fast-api service that is running into this. You've tried all the things people suggest about forking a new process to run the reactor-- none of it seems to work.
Stop what you're doing and go read this: https://github.com/notoriousno/scrapy-flask
Crochet is your best opportunity to get this working within gunicorn without writing your own crawler from scratch.
My way is multiprocessing use Process
#create spider
class PricesSpider(scrapy.Spider):
name = 'prices'
allowed_domains = ['index.minfin.com.ua']
start_urls = ['https://index.minfin.com.ua/ua/markets/fuel/tm/']
def parse(self, response):
pass
Than I create func which run my spider
#run spider
from scrapy.crawler import CrawlerRunner
from scrapy.utils.log import configure_logging
from twisted.internet import reactor
def parser():
configure_logging({'LOG_FORMAT': '%(levelname)s: %(message)s'})
runner = CrawlerRunner()
d = runner.crawl(PricesSpider)
d.addBoth(lambda _: reactor.stop())
reactor.run()
Than I create new Python file, import here func 'parser' and create schedule for my spider
#create schedule for spider
import schedule
from import parser
from multiprocessing import Process
def worker(pars):
print('Worker starting')
pr = Process(target=parser)
pr.start()
pr.join()
def main():
schedule.every().day.at("15:00").do(worker, parser)
# schedule.every().day.at("20:21").do(worker, parser)
# schedule.every().day.at("20:23").do(worker, parser)
# schedule.every(1).minutes.do(worker, parser)
print('Spider working now')
while True:
schedule.run_pending()
if __name__ == '__main__':
main()
I get twisted.internet.error.ReactorNotRestartable error when I execute following code:
from time import sleep
from scrapy import signals
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from scrapy.xlib.pydispatch import dispatcher
result = None
def set_result(item):
result = item
while True:
process = CrawlerProcess(get_project_settings())
dispatcher.connect(set_result, signals.item_scraped)
process.crawl('my_spider')
process.start()
if result:
break
sleep(3)
For the first time it works, then I get error. I create process variable each time, so what's the problem?
By default, CrawlerProcess's .start() will stop the Twisted reactor it creates when all crawlers have finished.
You should call process.start(stop_after_crawl=False) if you create process in each iteration.
Another option is to handle the Twisted reactor yourself and use CrawlerRunner. The docs have an example on doing that.
I was able to solve this problem like this. process.start() should be called only once.
from time import sleep
from scrapy import signals
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from scrapy.xlib.pydispatch import dispatcher
result = None
def set_result(item):
result = item
while True:
process = CrawlerProcess(get_project_settings())
dispatcher.connect(set_result, signals.item_scraped)
process.crawl('my_spider')
process.start()
For a particular process once you call reactor.run() or process.start() you cannot rerun those commands. The reason is the reactor cannot be restarted. The reactor will stop execution once the script completes the execution.
So the best option is to use different subprocesses if you need to run the reactor multiple times.
you can add the content of while loop to a function(say execute_crawling).
Then you can simply run this using different subprocesses. For this python Process module can be used.
Code is given below.
from multiprocessing import Process
def execute_crawling():
process = CrawlerProcess(get_project_settings())#same way can be done for Crawlrunner
dispatcher.connect(set_result, signals.item_scraped)
process.crawl('my_spider')
process.start()
if __name__ == '__main__':
for k in range(Number_of_times_you_want):
p = Process(target=execute_crawling)
p.start()
p.join() # this blocks until the process terminates
Ref http://crawl.blog/scrapy-loop/
import scrapy
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from twisted.internet import reactor
from twisted.internet.task import deferLater
def sleep(self, *args, seconds):
"""Non blocking sleep callback"""
return deferLater(reactor, seconds, lambda: None)
process = CrawlerProcess(get_project_settings())
def _crawl(result, spider):
deferred = process.crawl(spider)
deferred.addCallback(lambda results: print('waiting 100 seconds before
restart...'))
deferred.addCallback(sleep, seconds=100)
deferred.addCallback(_crawl, spider)
return deferred
_crawl(None, MySpider)
process.start()
I faced error ReactorNotRestartable on AWS lambda and after I came to this solution
By default, the asynchronous nature of scrapy is not going to work well with Cloud Functions, as we'd need a way to block on the crawl to prevent the function from returning early and the instance being killed before the process terminates.
Instead, we can use `
import scrapy
import scrapy.crawler as crawler
rom scrapy.spiders import CrawlSpider
import scrapydo
scrapydo.setup()
# your spider
class QuotesSpider(scrapy.Spider):
name = "quotes"
start_urls = ['http://quotes.toscrape.com/tag/humor/']
def parse(self, response):
for quote in response.css('div.quote'):
print(quote.css('span.text::text').extract_first())
scrapydo.run_spider(QuotesSpider)
` to run your existing spider in a blocking fashion:
I was able to mitigate this problem using package crochet via this simple code based on Christian Aichinger's answer to the duplicate of this question Scrapy - Reactor not Restartable.
The initialization of Spiders is done in the main thread whereas the particular crawling is done in different thread. I'm using Anaconda (Windows).
import time
import scrapy
from scrapy.crawler import CrawlerRunner
from crochet import setup
class MySpider(scrapy.Spider):
name = "MySpider"
allowed_domains = ['httpbin.org']
start_urls = ['http://httpbin.org/ip']
def parse(self, response):
print(response.text)
for i in range(1,6):
time.sleep(1)
print("Spider "+str(self.name)+" waited "+str(i)+" seconds.")
def run_spider(number):
crawler = CrawlerRunner()
crawler.crawl(MySpider,name=str(number))
setup()
for i in range(1,6):
time.sleep(1)
print("Initialization of Spider #"+str(i))
run_spider(i)
I had a similar issue using Spyder. Running the file from the command line instead fixed it for me.
Spyder seems to work the first time but after that it doesn't. Maybe the reactor stays open and doesn't close?
I could advice you to run scrapers using subprocess module
from subprocess import Popen, PIPE
spider = Popen(["scrapy", "crawl", "spider_name", "-a", "argument=value"], stdout=PIPE)
spider.wait()
If you're trying to get a flask or django or fast-api service that is running into this. You've tried all the things people suggest about forking a new process to run the reactor-- none of it seems to work.
Stop what you're doing and go read this: https://github.com/notoriousno/scrapy-flask
Crochet is your best opportunity to get this working within gunicorn without writing your own crawler from scratch.
My way is multiprocessing use Process
#create spider
class PricesSpider(scrapy.Spider):
name = 'prices'
allowed_domains = ['index.minfin.com.ua']
start_urls = ['https://index.minfin.com.ua/ua/markets/fuel/tm/']
def parse(self, response):
pass
Than I create func which run my spider
#run spider
from scrapy.crawler import CrawlerRunner
from scrapy.utils.log import configure_logging
from twisted.internet import reactor
def parser():
configure_logging({'LOG_FORMAT': '%(levelname)s: %(message)s'})
runner = CrawlerRunner()
d = runner.crawl(PricesSpider)
d.addBoth(lambda _: reactor.stop())
reactor.run()
Than I create new Python file, import here func 'parser' and create schedule for my spider
#create schedule for spider
import schedule
from import parser
from multiprocessing import Process
def worker(pars):
print('Worker starting')
pr = Process(target=parser)
pr.start()
pr.join()
def main():
schedule.every().day.at("15:00").do(worker, parser)
# schedule.every().day.at("20:21").do(worker, parser)
# schedule.every().day.at("20:23").do(worker, parser)
# schedule.every(1).minutes.do(worker, parser)
print('Spider working now')
while True:
schedule.run_pending()
if __name__ == '__main__':
main()
I want to run scrapy from a single script and I want to get all settings from settings.py but I would like to be able to change some of them:
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
process = CrawlerProcess(get_project_settings())
*### so what im missing here is being able to set or override one or two of the settings###*
# 'followall' is the name of one of the spiders of the project.
process.crawl('testspider', domain='scrapinghub.com')
process.start() # the script will block here until the crawling is finished
I wasn't able to use this. I tried the following:
settings=scrapy.settings.Settings()
settings.set('RETRY_TIMES',10)
but it didn't work.
Note: I'm using the latest version of scrapy.
So in order to override some settings, one way would be overriding/setting custom_settings, the spider's static variable, in our script.
so I imported the spider's class and then override the custom_setting:
from testspiders.spiders.followall import FollowAllSpider
FollowAllSpider.custom_settings={'RETRY_TIMES':10}
So this is the whole script:
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from testspiders.spiders.followall import FollowAllSpider
FollowAllSpider.custom_settings={'RETRY_TIMES':10}
process = CrawlerProcess(get_project_settings())
# 'followall' is the name of one of the spiders of the project.
process.crawl('testspider', domain='scrapinghub.com')
process.start() # the script will block here until the crawling is finished
For some reason, the above script didn't work for me. Instead I wrote the following and it works. Posting in case if anyone else falls into the same issue.
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
process = CrawlerProcess(get_project_settings())
process.settings.set(
'RETRY_TIMES', 10, priority='cmdline')
process.crawl('testspider', domain='scrapinghub.com')
process.start()
Ran into this problem myself and had a slightly different solution that uses a modern Python (>=3.5) approach
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
settings = {
**get_project_settings(),
'RETRY_TIMES': 2
}
process = CrawlerProcess(settings)
process.crawl('testspider', domain='scrapinghub.com')
process.start()
I have two spiders within the same project. One of them depends on the other running first. They use different pipelines. How can I make sure they are run sequentially?
Just from the doc:https://doc.scrapy.org/en/1.2/topics/request-response.html
Same example but running the spiders sequentially by chaining the deferreds:
from twisted.internet import reactor, defer
from scrapy.crawler import CrawlerRunner
from scrapy.utils.log import configure_logging
class MySpider1(scrapy.Spider):
# Your first spider definition
...
class MySpider2(scrapy.Spider):
# Your second spider definition
...
configure_logging()
runner = CrawlerRunner()
#defer.inlineCallbacks
def crawl():
yield runner.crawl(MySpider1)
yield runner.crawl(MySpider2)
reactor.stop()
crawl()
reactor.run() # the script will block here until the last crawl call is finished
I want to run some python code every 120 seconds.
I tried this:
class AppServerSvc :
def f(self):
# call f() again in 120 seconds
spider = FantasySerieaSpider()
settings = get_project_settings()
crawler = Crawler(settings)
crawler.signals.connect(reactor.stop, signal=signals.spider_closed)
crawler.configure()
crawler.crawl(spider)
crawler.start()
log.start()
reactor.run() # the script will block here until the spider_closed signal was sent
threading.Timer(120, f).start()
if __name__ == '__main__':
AppServerSvc().f();
I got the threading is not defined error
This are my imports:
import pythoncom
import win32serviceutil
import win32service
import win32event
import servicemanager
import socket
from twisted.internet import reactor
from scrapy.crawler import Crawler
from scrapy import log, signals
from FantasySeriea.spiders.spider import FantasySerieaSpider
from scrapy.utils.project import get_project_settings
from threading import Thread
rather than (or in addition to?):
from threading import Thread
you want:
import threading
You're using threading.Timer in your code but you're importing only Thread from threading and putting it into the current namespace. What you want is to import the whole module:
import threading
If you are using Thread, make sure to replace Thread by threading.Thread. Also, you are in a class, so you need to add self. in prefix or f to refer the class member:
threading.Timer(120, self.f).start()