code: def reverseComplement(seq):
      '''
      Helper function for generating reverse-complements
      '''
      revComp = ''
      complement = {'A':'T', 'C':'G', 'G':'C', 'T':'A', 'N':'N', '$':'$'}
      for c in reversed(seq):
          revComp += complement[c]
      return revComf reverseComplement(seq):
      '''
      Helper function for generating reverse-complements
      '''
      revComp = ''
      complement = {'A':'T', 'C':'G', 'G':'C', 'T':'A', 'N':'N', '$':'$'}
      for c in reversed(seq):
          revComp += complement[c]
      return revComp
docs: Helper function for generating reverse-complements