input: Write a python function to scrape and return the list of Presidents of the United States from a Wikipedia page.
  assert scrape_presidents()[:3] == ['George Washington', 'John Adams', 'Thomas Jefferson']
  assert scrape_presidents()[-3:] == ['Barack Obama', 'Donald Trump', 'Joe Biden']
  assert 'Abraham Lincoln' in scrape_presidents()
output: def scrape_presidents():
      import requests
      from bs4 import BeautifulSoup
  
      url = "https://en.wikipedia.org/wiki/List_of_presidents_of_the_United_States"
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      
      presidents = []
      table = soup.find('table', class_='wikitable')
      for row in table.find_all('tr')[1:]:
          columns = row.find_all('td')
          if columns:
              president = columns[3].text.strip()
              presidents.append(president)
      
      return presidents