<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def map_data(self, map_name):
 """Return the map data for a map by name or path."""

    with gfile.Open(os.path.join(self.data_dir, "Maps", map_name), "rb") as f:
      return f.read()