user: How can I write a python script to create a window that will display the titles and links to my "Watch Later" videos on Youtube?

assistant: To accomplish this task, you'll need to use the YouTube API to retrieve the list of videos from your Watch Later playlist, and a graphical user interface (GUI) toolkit to create a window to display the information.

Here's an example Python script using the `google-auth`, `google-auth-oauthlib`, `google-auth-httplib2`, `google-api-python-client`, and `tkinter` libraries to accomplish this:

```python
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
import tkinter as tk

# Set up credentials
creds = Credentials.from_authorized_user_file('credentials.json', ['https://www.googleapis.com/auth/youtube.readonly'])

# Set up YouTube API client
youtube = build('youtube', 'v3', credentials=creds)

# Get list of videos from Watch Later playlist
playlist_items = []
next_page_token = None
while True:
    request = youtube.playlistItems().list(
        part='snippet',
        playlistId='WL',
        maxResults=50,
        pageToken=next_page_token
    )
    response = request.execute()
    playlist_items += response['items']
    next_page_token = response.get('nextPageToken')
    if not next_page_token:
        break

# Create GUI window
root = tk.Tk()
root.title('Watch Later Videos')
root.geometry('600x400')

# Create listbox to display titles and links
listbox = tk.Listbox(root)
listbox.pack(expand=True, fill='both')

# Populate listbox with video titles and links
for item in playlist_items:
    title = item['snippet']['title']
    video_id = item['snippet']['resourceId']['videoId']
    link = f'https://www.youtube.com/watch?v={video_id}'
    listbox.insert('end', f'{title}: {link}')

# Start GUI event loop
root.mainloop()
```

Here's how the script works:

1. First, it sets up the `google-auth` and `google-api-python-client` libraries to authenticate with the YouTube API using OAuth2. You'll need to generate credentials for a project in the Google Cloud Console and save them to a `credentials.json` file in the same directory as the script.

2. It uses the `build()` function from the `googleapiclient.discovery` module to create a YouTube API client with the authenticated credentials.

3. It uses the `playlistItems().list()` method of the YouTube API client to retrieve the list of videos from your Watch Later playlist. The part parameter specifies that we want to retrieve the snippet data for each video, and the `maxResults` parameter specifies that we want to retrieve up to 50 videos at a time (the maximum allowed by the API). We loop through all pages of results using the `nextPageToken` field until we have retrieved all videos in the playlist.

4. It creates a `tkinter` window with a `Listbox` widget to display the video titles and links.

5. It loops through each video in the playlist, extracts the title and video ID from the `snippet` data, generates a link to the video using the video ID, and adds the title and link to the `Listbox`.

6. Finally, it starts the `tkinter` event loop to display the window and handle user interaction.

Note that this script assumes that you have already authenticated with the YouTube API and authorized access to your Watch Later playlist using OAuth2. If you haven't done this yet, you'll need to follow the instructions in the YouTube API documentation to set up authentication and authorization before running the script.