def negate_tips_to_keep(tips_to_keep, tree):
 tips_to_keep = set(tips_to_keep)
 tmp_tips = set([tip.Name for tip in tree.tips()])
 tips = set([t.strip("'").strip('"') for t in tmp_tips])
 return (tips - tips_to_keep)

def negate_tips_to_keep ( tips_to_keep , tree ) : tips_to_keep = set ( tips_to_keep ) tmp_tips = set ( [ tip . Name for tip in tree . tips ( ) ] ) tips = set ( [ t . strip ( "'" ) . strip ( '"' ) for t in tmp_tips ] ) return ( tips - tips_to_keep )
return the list of tips in the tree that are not in tips_to_keep .