input: Write a python function to get the current temperature of a given city from Google search.
  assert isinstance(get_temperature('San Francisco'), str)
  assert get_temperature('San Francisco').isdigit()
  assert len(get_temperature('San Francisco')) > 0
output: def get_temperature(city):
      import requests
      from bs4 import BeautifulSoup
  
      query = f"weather {city}"
      url = f"https://www.google.com/search?q={query}"
      headers = {
          "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36"
      }
      
      response = requests.get(url, headers=headers)
      soup = BeautifulSoup(response.content, "html.parser")
      
      temperature = soup.find("span", {"id": "wob_tm"}).text
      return temperature