code: def rewriteFasta(sequence, sequence_name, fasta_in, fasta_out):
      
      f=open(fasta_in, 'r+')
      f2=open(fasta_out,'w')
      lines = f.readlines()
      i=0
      while i < len(lines):
          line = lines[i]
          if line[0] == ">":
              f2.write(line)
              fChr=line.split(" ")[0]
              fChr=fChr[1:]
              if fChr == sequence_name:
                  code=['N','A','C','T','G']
                  firstbase=lines[i+1][0]
                  while firstbase in code:
                      i=i+1
                      firstbase=lines[i][0]
                  s=0
                  while s <= len(sequence):
                      f2.write(sequence[s:s+60]+"\n")
                      s=s+60
              else:
                  i=i+1
          else:
              f2.write(line)
              i=i+1
  
      f2.close
      f.close
docs: Rewrites a specific sequence in a multifasta file while keeping the sequence header.
  
      :param sequence: a string with the sequence to be written
      :param sequence_name: the name of the sequence to be retrieved eg. for '>2 dna:chromosome chromosome:GRCm38:2:1:182113224:1 REF' use: sequence_name=str(2)
      :param fasta_in: /path/to/original.fa
      :param fasta_out: /path/to/destination.fa
  
      :returns: nothing