#NEWLINE# def __sub__( self , other ) : #NEWLINE# #INDENT# "\n        Subtract count, but keep only results with positive counts.\n\n        >>> FreqDist('abbbc') - FreqDist('bccd')\n        FreqDist({'b': 2, 'a': 1})\n\n        " #NEWLINE# return self . __class__ ( super ( FreqDist , self ) . __sub__ ( self ) )