Repeatedly scrape data from same url with a time delay

I am trying to consistently scrape a single webpage over a period of time to monitor some values and how they are changing within that period

I have no experience in web-scraping and I'm a little confused as to why my scrapy spider runs once and hangs.

I am attempting to run the spider through a 'main.py' script as follows:

timecheck = timeit.default_timer()

while (timecheck) < 30:
    if __name__ == "__main__":
        settings = get_project_settings()
        crawler = CrawlerProcess(settings)
        crawler.crawl(mySpider())
        crawler.start(stop_after_crawl=False)
    time.sleep(5)

print("Finished crawl, time elapsed: %s" % str(timecheck))

My spider script is as follows:

class poeSpider(scrapy.Spider):
    name = "spidername"

    def start_requests(self):
        urls = ["myurl.com/page1"]
        allowed_domains = ["myurl.com"]

        for url in urls:
            yield scrapy.Request(url=url, callback=self.parse, dont_filter=True)


    def parse(self,response):

        datavar = response.xpath("/mydata").extract()
        print(datavar[:3])

PS: A different issue, but related:

I'm also looking to store the data in a list or variable of some kind between scrapes so that I am able to compare the values while the program is running, ideally without any file I/O, which is my reasoning for using a 'main.py' though I'm also at a loss for how to pass the data in the parse function of the spider to anywhere where I can make such comparisons.