code: def phred_13_to_18_sed(self, new_path=None, in_place=True):
          
          # String #
          sed_command = r"""4~4y/@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghi/!"#$%&'\''()*+,-.\/0123456789:;<=>?@ABCDEFGHIJ/"""
          # Faster with bash utilities #
          if in_place is True:
              sh.sed('-i', sed_command, self.path)
              return self
          # New file #
          if new_path is None: new_fastq = self.__class__(new_temp_path())
          else:                new_fastq = self.__class__(new_path)
          sh.sed(sed_command + " " + new_fastq, self.path)
          return new_fastq
docs: Illumina-1.3 format conversion to Illumina-1.8 format via sed (faster).