from bs4 import BeautifulSoup
links = []
# получаем ссылки из файла
with open('index.html', 'r', encoding='utf-8') as f:
    data = f.read()
    soup = BeautifulSoup(data, "html.parser")
    links = soup.find_all('a')
# выводим их в консоль
for link in links:
    print(link['href'])
# записываем в файл file.txt
with open('file.txt', 'w', encoding='utf-8') as f:
    for link in links:
        f.write(link['href'] + '\n')

[code python]Traceback (most recent call last):
  File "1.py", line 12, in <module>
    print(link['href'])
  File "C:\Python38-32\lib\site-packages\bs4\element.py", line 1406, in __getite
m__
    return self.attrs[key]
KeyError: 'href'
------------------
(program exited with code: 1)[/code]