save clipboard image to file

saveclip.py

#!/usr/bin/env python
#
# the code is in public domain
# gist:4009c397f8f8aff31a46
#
# history:
#   1.2  - rename to saveclip.py
#   1.1  - mention what library should be installed
#   1.0  - make get_avail_filename() function

__version__ = '1.2'

import os, sys
try:
    from PIL import ImageGrab
except ImportError:
    # https://github.com/python-pillow/Pillow/issues/1293
    raise ImportError("Pillow is not installed (use Pillow>=3.3.0)")

def get_avail_filename(basename, suffix='%0.2d.png'):
    """Find first non-existing filename with given numerical suffix"""
    counter = 1
    while True:
        newname = basename + suffix % counter
        if not os.path.exists(newname):
            return newname
        counter += 1

filename = 'clipboard.png'
if os.path.exists(filename):
  filename = get_avail_filename('clipboard', suffix='%0.2d.png')

im = ImageGrab.grabclipboard()
if im is None:
  sys.exit('Error: No image data in clipboard')
else:
  im.save(filename, 'PNG')
  print('Saved as %s' % filename)