<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _ensure_filepath(filename):
 """ Ensure that the directory exists before trying to write to the file. """


        filepath = os.path.dirname(filename)
        if not os.path.exists(filepath):
            os.makedirs(filepath)