old_contents: # -*- coding: utf-8 -*-
  #
  #  This file is part of Sequana software
  #
  #  Copyright (c) 2016 - Sequana Development Team
  #
  #  File author(s):
  #      Thomas Cokelaer <thomas.cokelaer@pasteur.fr>
  #      Dimitri Desvillechabrol <dimitri.desvillechabrol@pasteur.fr>, 
  #          <d.desvillechabrol@gmail.com>
  #
  #  Distributed under the terms of the 3-clause BSD license.
  #  The full license is in the LICENSE file, distributed with this software.
  #
  #  website: https://github.com/sequana/sequana
  #  documentation: http://sequana.readthedocs.io
  #
  ##############################################################################
  import itertools
  
  def build_kmer(length=6, letters='CG'):
      # build permutations of CG letters with a sequence of given lengths
      # TODO include N other letters
      combos = list(itertools.product(letters, repeat=length))
      return ["".join(this) for this in combos]
  
  
  def get_kmer(sequence, k=7):
      for i in range(0, len(sequence)-k+1):
          yield sequence[i:i+k]
  
new_contents: # -*- coding: utf-8 -*-
  #
  #  This file is part of Sequana software
  #
  #  Copyright (c) 2016 - Sequana Development Team
  #
  #  File author(s):
  #      Thomas Cokelaer <thomas.cokelaer@pasteur.fr>
  #      Dimitri Desvillechabrol <dimitri.desvillechabrol@pasteur.fr>, 
  #          <d.desvillechabrol@gmail.com>
  #
  #  Distributed under the terms of the 3-clause BSD license.
  #  The full license is in the LICENSE file, distributed with this software.
  #
  #  website: https://github.com/sequana/sequana
  #  documentation: http://sequana.readthedocs.io
  #
  ##############################################################################
  import itertools
  
  
  def build_kmer(length=6, letters='CG'):
      """Return list of kmer of given length based on a set of letters
  
      :return: list of kmers
      """
      # build permutations of CG letters with a sequence of given lengths
      # TODO include N other letters
      combos = list(itertools.product(letters, repeat=length))
      return ["".join(this) for this in combos]
  
  
  def get_kmer(sequence, k=7):
      """Given a sequence, return consecutive kmers
  
  
      :return: iterator of kmers
  
      """
      for i in range(0, len(sequence)-k+1):
          yield sequence[i:i+k]
  
subject: add docstrings