How to add random user agent to scrapy spider when calling spider from script?

I want to add random user agent to every request for a spider being called by other script. My implementation is as follows:

CoreSpider.py

from scrapy.spiders import Rule
import ContentHandler_copy 

class CoreSpider(scrapy.Spider):
name = "final"
def __init__(self):
    self.start_urls = self.read_url()
    self.rules = (
        Rule(
            LinkExtractor(
                unique=True,
            ),
            callback='parse',
            follow=True
        ),
    )


def read_url(self):
    urlList = []
    for filename in glob.glob(os.path.join("/root/Public/company_profiler/seed_list", '*.list')):
        with open(filename, "r") as f:
            for line in f.readlines():
                url = re.sub('n', '', line)
                if "http" not in url:
                    url = "http://" + url
                # print(url)
                urlList.append(url)

    return urlList

def parse(self, response):
    print("URL is: ", response.url)
    print("User agent is : ", response.request.headers['User-Agent'])
    filename = '/root/Public/company_profiler/crawled_page/%s.html' % response.url
    article = Extractor(extractor='LargestContentExtractor', html=response.body).getText()
    print("Article is :", article)
    if len(article.split("n")) < 5:
        print("Skipping to next url : ", article.split("n"))
    else:
        print("Continue parsing: ", article.split("n"))
        ContentHandler_copy.ContentHandler_copy.start(article, response.url)

I am running this spider from a script as follows by RunSpider.py

from CoreSpider import CoreSpider
from scrapy.crawler import  CrawlerProcess



process = CrawlerProcess()
process.crawl(CoreSpider())
process.start()

It works fine, now I want to randomly use different user-agent for each request. I have successfully used random user-agent for scrapy project, but unable to integrate with this spider when calling this spider from other script.

My settings.py for working scrapy project –

BOT_NAME = 'tutorial'

SPIDER_MODULES = ['tutorial.spiders']
NEWSPIDER_MODULE = 'tutorial.spiders'


# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'tutorial (+http://www.yourdomain.com)'

DOWNLOADER_MIDDLEWARES = {
'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': None,
'random_useragent.RandomUserAgentMiddleware': 320
}

USER_AGENT_LIST = "tutorial/user-agent.txt"

How can I tell my CoreSpider.py to use this setting.py configuration programmatically?