code: def read_input_file(filename, sep='\t', noquote=False):
      
      output = []
      stream = None
      try:
          stream = open(filename, 'r')
          for row in stream:
              row = row.strip()
              if noquote:
                  row = row.replace('"', '')
              output.append(row.split(sep))
      except IOError as err:  # pragma: no cover
          LOG.info("Something wrong happend while reading the file %s "
                   % filename)
          LOG.debug("ERROR: %s" % err)
      finally:
          if stream:
              stream.close()
      return output
docs: Reads a given inputfile (tab delimited) and returns a matrix
      (list of list).
      arg: filename, the complete path to the inputfile to read