new_contents: #Kunal Gautam
  #Codewars : @Kunalpod
  #Problem name: Complementary DNA
  #Problem level: 7 kyu
  
  dna_c = {'A':'T', 'T':'A', 'G':'C', 'C':'G'}
  def DNA_strand(dna):
      return ''.join(dna_c[x] for x in dna)
  
subject: Create complementary_dna.py