Created the basic structure of the code.

main.py

@@ -1,6 +1,28 @@
+from pytube import YouTube
+
+# Asks the User for a youtube video URL.
+def get_video_url():
+    try:
+        video_url = input('YouTube video URL: ')
+        return video_url
+    except Exception as e:
+        print(f"An error has occured: {e}")
+
+# Download the video.
+def video_download(video_url):
+    try:
+        youtube = YouTube(video_url)
+        video = youtube.streams.get_highest_resolution()
+        video.download()
+    except Exception as e:
+        print(f"An error has occured: {e}")
+
 def main():
     try:
-        print()
+        video_url = get_video_url()
+        video_download(video_url)
+    except KeyboardInterrupt:
+        print("Session ended by user.")
     except Exception as e:
         print(f"{e}")