input: Write a function to create a virtual assistant using Python and Dialogflow to answer a basic set of questions. The function should continuously prompt the user for input, process the input using Dialogflow, and print the assistant's response. If the user types 'exit', the function should terminate.
  
  
  def create_virtual_assistant(project_id, session_id):
      import dialogflow_v2 as dialogflow
      session_client = dialogflow.SessionsClient()
      session = session_client.session_path(project_id, session_id)
      
      while True:
          text = input('User: ')
          if text.lower() == 'exit':
              break
          text_input = dialogflow.types.TextInput(text=text, language_code='en-US')
          query_input = dialogflow.types.QueryInput(text=text_input)
          response = session_client.detect_intent(session=session, query_input=query_input)
          
          print('Assistant:', response.query_result.fulfillment_text)
  
  assert create_virtual_assistant('project-id', 'session-id') is None
  
output: def create_virtual_assistant(project_id, session_id):
      import dialogflow_v2 as dialogflow
      session_client = dialogflow.SessionsClient()
      session = session_client.session_path(project_id, session_id)
      
      while True:
          text = input('User: ')
          if text.lower() == 'exit':
              break
          text_input = dialogflow.types.TextInput(text=text, language_code='en-US')
          query_input = dialogflow.types.QueryInput(text=text_input)
          response = session_client.detect_intent(session=session, query_input=query_input)
          
          print('Assistant:', response.query_result.fulfillment_text)