code: def rev_comp(seq):
      
      rev_seq = seq[::-1]
      rev_comp_seq = ''.join([base_pairing[s] for s in rev_seq])
      return rev_comp_seq
docs: Get reverse complement of sequence.
  
      rev_comp will maintain the case of the sequence.
  
      Parameters
      ----------
      seq : str
          nucleotide sequence. valid {a, c, t, g, n}
  
      Returns
      -------
      rev_comp_seq : str
          reverse complement of sequence