How to use the polib.mofile function in polib

def test_translated_messages(self, locale):
        message_dir = LOCALE_DIR / locale / 'LC_MESSAGES'
        for pofile_name in self.PO_FILES:
            pofile_path = message_dir / pofile_name
            pofile = polib.pofile(pofile_path)
            mofile = polib.mofile(pofile_path.stripext() + '.mo')

            po_entries = {entry.msgid: entry for entry in pofile.translated_entries()}
            mo_entries = {entry.msgid: entry for entry in mofile.translated_entries()}

            # Check that there are no entries in po that aren't in mo, and vice-versa
            self.assertEquals(po_entries.viewkeys(), mo_entries.viewkeys())

            for entry_id, po_entry in po_entries.items():
                mo_entry = mo_entries[entry_id]
                for attr in ('msgstr', 'msgid_plural', 'msgstr_plural', 'msgctxt', 'obsolete', 'encoding'):
                    po_attr = getattr(po_entry, attr)
                    mo_attr = getattr(mo_entry, attr)

                    # The msgstr_plural in the mo_file is keyed on ints, but in the po_file it's
                    # keyed on strings. This normalizes them.
                    if attr == 'msgstr_plural':

def load_files(self):
        num_files = 0
        for root, subFolders, files in os.walk(os.getcwd(),topdown=False):
            for file in files:
                if self.type == MO_EXT and file.endswith(MO_EXT):
                    num_files += 1
                elif file.endswith(PO_EXT):
                    num_files += 1

        count_files = 0
        for root, subFolders, files in os.walk(os.getcwd(),topdown=False):
            for file in files:
                if self.type == MO_EXT and file.endswith(MO_EXT):
                    path, junk = os.path.split(root)
                    path, locale = os.path.split(path)
                    mo_inst = polib.mofile(os.path.join(root, file))
                    mo = Mo(mo_inst, locale, os.path.join(root, file))
                elif file.endswith(PO_EXT):
                    mo_inst = polib.pofile(os.path.join(root, file))
                    mo = Mo(mo_inst, file, os.path.join(root, file))
                    if mo.locale in UNSUPPORTED_LOCALES:
                        # Don't check PO files for some of the locales (right-to-left languages for instance, or languages where it's hard for us to verify the arguments)
                        continue
                else:
                    continue
                count_files += 1
                self.check_file(mo)
                self.report_progress(count_files, num_files)