<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def load_lst(self):
 """ Load the lst file into internal data structures """

        with open(self._lst_file, 'r') as fd:
            lines = fd.readlines()

        idx, uname, fname = list(), list(), list()

        for line in lines:
            values = line.split(',')
            values = [x.strip() for x in values]

            # preserve the idx ordering here in case variables are not
            # ordered by idx
            idx.append(int(values[0]))  # convert to integer
            uname.append(values[1])
            fname.append(values[2])

        self._idx = idx
        self._fname = fname
        self._uname = uname