CSV writer writes set to a single row rather than multiple rows - python-3.x

Question

I am working on a web scraper for class. I basically have to compile all of the http links from a website and write them to a csv. They also need to be de-duplicated which is why I'm using a set. I have all the parts complete expect when it writes to the csv, the entire set of links writes to a single row rather than one link per row. Can someone review my code and tell me what i'm missing? I cannot find a solution anywhere.
My code is below:
from bs4 import BeautifulSoup
import requests
import csv
import urllib.parse
base_url = 'https://www.census.gov'
l = set()
r = requests.get("https://www.census.gov/programs-surveys/popest.html")
c = r.content
soup = BeautifulSoup(c, 'html.parser')
file = open('c996webscraper_writer.csv', 'w', newline="")
for link in soup.findAll('a'):
output = link.get('href')
abs_url = urllib.parse.urljoin(base_url, output)
l.add(abs_url)
with file:
write = csv.writer(file, delimiter = ',', lineterminator = '\r')
write.writerow(['List of Links'])
write.writerows([l])
file.close()
This is a printout of what's happening:
CSV Image

Answer 1

from bs4 import BeautifulSoup
import requests
import csv
import urllib.parse
base_url = 'https://www.census.gov'
l = list()
r = requests.get("https://www.census.gov/programs-surveys/popest.html")
c = r.content
soup = BeautifulSoup(c, 'html.parser')
file = open('c996webscraper_writer.csv', 'w', newline="")
for link in soup.findAll('a'):
output = link.get('href')
abs_url = urllib.parse.urljoin(base_url, output)
l.append(abs_url)
with file:
write = csv.writer(file)
write.writerow(['List of Links'])
for x in l:
write.writerow([x])
file.close()