old_contents: #*****************************************************************************
  #   Copyright 2004-2008 Steve Menard
  #
  #   Licensed under the Apache License, Version 2.0 (the "License");
  #   you may not use this file except in compliance with the License.
  #   You may obtain a copy of the License at
  #
  #       http://www.apache.org/licenses/LICENSE-2.0
  #
  #   Unless required by applicable law or agreed to in writing, software
  #   distributed under the License is distributed on an "AS IS" BASIS,
  #   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #   See the License for the specific language governing permissions and
  #   limitations under the License.
  #   
  #*****************************************************************************
  
  import sets
  
  KEYWORDS = sets.Set( (
      "del", "for", "is", "raise",
      "assert", "elif", "from", "lambda", "return",   
      "break", "else", "global", "not", "try",
      "class", "except", "if", "or", "while", 
      "continue", "exec", "import", "pass", "yield",
      "def", "finally", "in", "print", "as", "None"
      ))
  
  
new_contents: #*****************************************************************************
  #   Copyright 2004-2008 Steve Menard
  #
  #   Licensed under the Apache License, Version 2.0 (the "License");
  #   you may not use this file except in compliance with the License.
  #   You may obtain a copy of the License at
  #
  #       http://www.apache.org/licenses/LICENSE-2.0
  #
  #   Unless required by applicable law or agreed to in writing, software
  #   distributed under the License is distributed on an "AS IS" BASIS,
  #   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #   See the License for the specific language governing permissions and
  #   limitations under the License.
  #
  #*****************************************************************************
  KEYWORDS = set(
      "del", "for", "is", "raise",
      "assert", "elif", "from", "lambda", "return",
      "break", "else", "global", "not", "try",
      "class", "except", "if", "or", "while",
      "continue", "exec", "import", "pass", "yield",
      "def", "finally", "in", "print", "as", "None"
  )
  
subject: use native sets instead of set module.