code: def parse_dir_for_io_files(d):
      
  
      files = os.listdir(d)
      tpl_files = [f for f in files if f.endswith(".tpl")]
      in_files = [f.replace(".tpl","") for f in tpl_files]
      ins_files = [f for f in files if f.endswith(".ins")]
      out_files = [f.replace(".ins","") for f in ins_files]
      return tpl_files,in_files,ins_files,out_files
docs: a helper function to find template/input file pairs and
      instruction file/output file pairs.  the return values from this
      function can be passed straight to pyemu.Pst.from_io_files() classmethod
      constructor. Assumes the template file names are <input_file>.tpl and
      instruction file names are <output_file>.ins.
  
      Parameters
      ----------
      d : str
          directory to search for interface files
  
      Returns
      -------
      tpl_files : list
          list of template files in d
      in_files : list
          list of input files in d
      ins_files : list
          list of instruction files in d
      out_files : list
          list of output files in d