[kovidgoyal]

You can just do this:

try:
    from calibre_plugins.count_pages.common_utils import (get_library_uuid, CustomColumnComboBox,
                                     KeyboardConfigDialog, KeyValueComboBox, PrefsViewerDialog)
except ImportError:
    from common_utils import (get_library_uuid, CustomColumnComboBox,
                                     KeyboardConfigDialog, KeyValueComboBox, PrefsViewerDialog)

And if you want to detect if you are running in a full calibre environment, use this:

import sys
in_calibre = hasattr(sys, 'extensions_location')