input: 下面我将按照您提供的格式，生成一个问题：
  
  
  def virtual_assistant_using_dialogflow() -> None:
      """Create a virtual assistant using Python and Dialogflow to answer a basic set of questions.
      The user will input text through the console, and the assistant will respond using Dialogflow's
      detect_intent method. The session is set up with a predefined project_id and session_id, and
      the conversation loop will continue indefinitely until the program is terminated.
      Example:
      >>> virtual_assistant_using_dialogflow()
      User: What's the weather today?
      Assistant: The weather today is sunny with a high of 75 degrees.
      User: Exit
      """
  
output:     
      import dialogflow_v2 as dialogflow
      import os
  
      os.environ["GOOGLE_APPLICATION_CREDENTIALS"] = "path_to_your_credentials_file.json"
  
      project_id = "your_project_id"
      session_id = "your_session_id"
      language_code = "en-US"
  
      session_client = dialogflow.SessionsClient()
      session = session_client.session_path(project_id, session_id)
  
      while True:
          user_input = input("User: ")
          if user_input.lower() == "exit":
              break
  
          text_input = dialogflow.types.TextInput(text=user_input, language_code=language_code)
          query_input = dialogflow.types.QueryInput(text=text_input)
  
          response = session_client.detect_intent(session=session, query_input=query_input)
  
          print(f"Assistant: {response.query_result.fulfillment_text}")
  