added error handling for api key missing

main.py

@@ -3,6 +3,14 @@ import os
 from openai import OpenAI 
 from pytube import YouTube
 
+def get_api_key():
+    try:
+        OPENAI_API_KEY = os.environ.get('OPENAI_API_KEY')
+        return OPENAI_API_KEY
+    except Exception as e:
+        print(f"Failed to retrieve OpenAI API Key: {e}")
+        return None
+
 # Downloads the audio from a YouTube video.
 def download(video_url, output_filename='audio.mp4'):
     try:
@@ -71,14 +79,18 @@ def cleanup(audio_filename):
 # Main function to orchestrate the download, transcription, summarization, and cleanup process.
 def main():
     try:
-        OPENAI_API_KEY = os.environ.get('OPENAI_API_KEY')
-        video_url = str(input("video url:"))
+        OPENAI_API_KEY = get_api_key()
+        video_url = str(input("Video url: "))
         audio_filename = download(video_url)
+        if audio_filename is not None:
             transcript = transcription(OPENAI_API_KEY, audio_filename)
+            if transcript is not None:
                 summary(OPENAI_API_KEY, transcript)
             cleanup(audio_filename)
     except Exception as e:
         print(e)
+    finally:
+        input("Press Enter to exit...")
 
 if __name__ == "__main__":
     main()