input: Write a function to get current weather of a city using OpenWeatherMap API.
  assert get_weather("London") != 'City not found!'
  assert get_weather("InvalidCityName") == 'City not found!'
  assert 'The Temperature in' in get_weather("New York")
output: def get_weather(city):
      import requests
      
      api_key = "your_api_key_here"
      base_url = "http://api.openweathermap.org/data/2.5/weather?"
      
      complete_url = base_url + "q=" + city + "&appid=" + api_key + "&units=metric"
      
      response = requests.get(complete_url)
      
      if response.status_code == 200:
          data = response.json()
          if data["cod"] != "404":
              main = data["main"]
              temperature = main["temp"]
              weather_description = data["weather"][0]["description"]
              return f"The Temperature in {city} is {temperature}°C with {weather_description}."
          else:
              return 'City not found!'
      else:
          return 'City not found!'