When I use Google Colaboratory, how to save image, weights in my Google Drive?

You need to mount google drive to your Colab session.

from google.colab import drive
drive.mount('/content/gdrive')

Then you can simply write to google drive as you would to a local file system like so:

with open('/content/gdrive/My Drive/file.txt', 'w') as f:
  f.write('content')