How would I prevent adding multiple copies of the same data to my firebase database

Question

I am designing a small sports news app as a school project that scrapes data from the web, posts it to a firebase realtime database and is then used in an application being built on android studio by my project partner. So far during development I have just been deleting the database and rebuilding it every time i run the code to prevent build-up of the same data. I am wondering how i would go about checking to see if a piece of data exists before it push the data to the database. Thanks if anyone is able to point me in the right direction. Here is my code for pushing the data to firebase:

ref = db.reference('/news')
ref.delete()

url = 'https://news.sky.com/topic/premier-league-3810'
content = requests.get(url)
soup = BeautifulSoup(content.text, "html.parser")
body = soup.find_all("h3", "sdc-site-tile__headline")

titles_list = []
links_list = []
for item in body:
    headline = item.find_all('span', class_='sdc-site-tile__headline-text')[0].text
    titles_list.append(headline)

    link = item.find('a', class_='sdc-site-tile__headline-link').get('href')
    links_list.append('https://news.sky.com'  + link)

i=0
while i < len(titles_list):
    ref.push({
        'Title' : titles_list[i],
        'Link' : links_list[i] 
    })
    i+=1