input: Write a python function to create a Flask app that returns a description for the animal 'Lion' when submitted through a form.
  assert get_animal_description('Lion') == 'The lion is a large mammal of the family Felidae. It is a formidable and famous predator of the African savanna. It has a majestic presence and strength.'
  assert get_animal_description('Tiger') == 'No description available.'
  assert get_animal_description('') == 'No description available.'
output: from flask import Flask, request, render_template_string
  
  app = Flask(__name__)
  
  def get_animal_description(animal):
      descriptions = {
          "Lion": "The lion is a large mammal of the family Felidae. It is a formidable and famous predator of the African savanna. It has a majestic presence and strength."
      }
      return descriptions.get(animal, "No description available.")
  
  @app.route('/', methods=['GET', 'POST'])
  def home():
      description = ''
      if request.method == 'POST':
          animal = request.form.get('animal', '')
          description = get_animal_description(animal)
      return render_template_string('''
          <form method="post">
              Animal: <input type="text" name="animal">
              <input type="submit">
          </form>
          <p>{{ description }}</p>
      ''', description=description)
  
  if __name__ == '__main__':
      app.run(debug=True)