You can use this script as an example, how to filter the links:
import requests
from bs4 import BeautifulSoup
url = 'https://unsplash.com'
soup = BeautifulSoup(requests.get(url).content, 'html.parser')
for img in soup.find_all('img'):
if 'photo' in img['src']: # print only links with `photo` inside them
print(img['src'])
Prints:
https://images.unsplash.com/photo-1597649260558-e2bd7d35f043?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format%2Ccompress&fit=crop&w=1000&h=1000
https://images.unsplash.com/photo-1598929214025-d6bb6167d43b?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1599567513879-604247ea2bd3?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1599366611308-719895c34512?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1598929214025-d6bb6167d43b?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1599366611308-719895c34512?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1599567513879-604247ea2bd3?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1598929214025-d6bb6167d43b?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1599567513879-604247ea2bd3?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
https://images.unsplash.com/photo-1599366611308-719895c34512?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80
With urllib:
import urllib.request
from bs4 import BeautifulSoup
url = 'https://unsplash.com'
soup = BeautifulSoup(urllib.request.urlopen(url).read(), 'html.parser')
for img in soup.find_all('img'):
if 'photo' in img['src']:
print(img['src'])