input: Write a function to scrape price and description from a website using requests and BeautifulSoup.
  assert scrape_price_description('https://example.com/product1')==('Price: $19.99', 'Description: A nice product.')
  assert scrape_price_description('https://example.com/product2')==('Price: $29.99', 'Description: Another great product.')
  assert scrape_price_description('https://example.com/product3')==('Price: $39.99', 'Description: Yet another amazing product.')
output: def scrape_price_description(url):
      import requests
      from bs4 import BeautifulSoup
      
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
      
      # Assuming the price is in a span with class 'price' and description in a div with class 'description'
      price = soup.find('span', class_='price').text
      description = soup.find('div', class_='description').text
      
      return f'Price: {price}', f'Description: {description}'