code: def SAMflags(x):
      flags=[]
      if x & 1:
          l="1: Read paired"
      else:
          l="0: Read unpaired"
      flags.append(l)
      if x & 2 :
          l="1: Read mapped in proper pair"
      else:
          l="0: Read not mapped in proper pair"
      flags.append(l)
      if x & 4 :
          l="1: Read unmapped"
      else:
          l="0: Read mapped"
      flags.append(l)
      if x & 8 :
          l="1: Mate unmapped"
      else:
          l="0: Mate mapped"
      flags.append(l)
      if x & 16 :
          l="1: Read reverse strand"
      else:
          l="0: Read direct strand"
      flags.append(l)
      if x & 32 :
          l="1: Mate reverse strand"
      else:
          l="0: Mate direct strand"
      flags.append(l)
      if x & 64 :
          l="1: First in pair"
      else:
          l="0: Second in pair"
      flags.append(l)
      if x & 128 :
          l="1: Second in pair"
      else:
          l="0: First in pair"
      flags.append(l)
      if x & 256 :
          l="1: Not primary alignment"
      else:
          l="0: Primary alignment"
      flags.append(l)
      if x & 512 :
          l="1: Read fails platform/vendor quality checks"
      else:
          l="0: Read passes platform/vendor quality checks"
      flags.append(l)
      if x & 1024 :
          l="1: Read is PCR or optical duplicate"
      else:
          l="0: Read is not PCR or optical duplicate"
      flags.append(l)
      if x & 2048 :
          l="1: Supplementary alignment"
      else:
          l="0: Not supplementary alignment"
      flags.append(l)
      return flags