docs: def main():
      """
      NAME 
          update_measurements.py
  
      DESCRIPTION
          update the magic_measurements table with new orientation info
   
      SYNTAX
          update_measurements.py [command line options]
  
      OPTIONS
          -h prints help message and quits
          -f MFILE, specify magic_measurements file; default is magic_measurements.txt
          -fsa SFILE, specify er_samples table; default is er_samples.txt
          -F OFILE, specify output file, default is same as MFILE
      """
      dir_path='.'
      meas_file='magic_measurements.txt'
      samp_file="er_samples.txt"
      out_file='magic_measurements.txt'
      if '-h' in sys.argv:
          print(main.__doc__)
          sys.exit()
      if '-WD' in sys.argv:
          ind = sys.argv.index('-WD')
          dir_path=sys.argv[ind+1]
      if '-f' in sys.argv:
          ind = sys.argv.index('-f')
          meas_file=sys.argv[ind+1]
      if '-fsa' in sys.argv:
          ind = sys.argv.index('-fsa')
          samp_file=sys.argv[ind+1]
      if '-F' in sys.argv:
          ind = sys.argv.index('-F')
          out_file=sys.argv[ind+1]
      # read in measurements file
      meas_file=dir_path+'/'+meas_file
      out_file=dir_path+'/'+out_file
      samp_file=dir_path+'/'+samp_file
      data,file_type=pmag.magic_read(meas_file)
      samps,file_type=pmag.magic_read(samp_file)
      MeasRecs=[]
      sampnames,sflag=[],0
      for rec in data:
          for samp in  samps:
              if samp['er_sample_name'].lower()==rec['er_sample_name'].lower():
                  if samp['er_sample_name'] not in sampnames:sampnames.append(samp['er_sample_name'].lower())
                  rec['er_site_name']=samp['er_site_name']
                  rec['er_location_name']=samp['er_location_name']
                  MeasRecs.append(rec)
                  break
          if rec['er_sample_name'].lower() not in sampnames:
              sampnames.append(rec['er_sample_name'].lower())
              sflag=1
              SampRec={}
              for key in list(samps[0].keys()):SampRec[key]=""
              SampRec['er_sample_name']=rec['er_sample_name']
              SampRec['er_citation_names']="This study"
              SampRec['er_site_name']='MISSING'
              SampRec['er_location_name']='MISSING'
              SampRec['sample_desription']='recorded added by update_measurements - edit as needed'
              samps.append(SampRec)
              print(rec['er_sample_name'],' missing from er_samples.txt file - edit orient.txt file and re-import')
              rec['er_site_name']='MISSING'
              rec['er_location_name']='MISSING'
              MeasRecs.append(rec)
      pmag.magic_write(out_file,MeasRecs,'magic_measurements')
      print("updated measurements file stored in ", out_file)
      if sflag==1:
           pmag.magic_write(samp_file,samps,'er_samples')
           print("updated sample file stored in ", samp_file)