code: def _subset_table(full_table, subset):
      
      if not subset:
          return full_table
  
      # TODO: Figure out syntax for logical or
      conditions = subset.replace(' ','').split(';')
  
      valid = np.ones(len(full_table), dtype=bool)
      for condition in conditions:
          col = re.split("[<>=!]", condition)[0]
          comp = condition.replace(col, "")
          try:
              this_valid = eval("full_table['{0}']{1}".format(col, comp))
          except KeyError as e: # catch error and redisplay for twiggy
              raise KeyError("Column '%s' not found" % e.message)
          valid = np.logical_and(valid, this_valid)
  
      return full_table[valid]
docs: Return subtable matching all conditions in subset
  
      Parameters
      ----------
      full_table : dataframe
          Entire data table
      subset : str
          String describing subset of data to use for analysis
  
      Returns
      -------
      dataframe
          Subtable with records from table meeting requirements in subset