base.py 文件源码

def execute(self, *args, **options):
        """
        Try to execute this command, performing system checks if needed (as
        controlled by the ``requires_system_checks`` attribute, except if
        force-skipped).
        """
        if options['no_color']:
            self.style = no_style()
            self.stderr.style_func = None
        if options.get('stdout'):
            self.stdout = OutputWrapper(options['stdout'])
        if options.get('stderr'):
            self.stderr = OutputWrapper(options['stderr'], self.stderr.style_func)

        saved_locale = None
        if not self.leave_locale_alone:
            # Only mess with locales if we can assume we have a working
            # settings file, because django.utils.translation requires settings
            # (The final saying about whether the i18n machinery is active will be
            # found in the value of the USE_I18N setting)
            if not self.can_import_settings:
                raise CommandError("Incompatible values of 'leave_locale_alone' "
                                   "(%s) and 'can_import_settings' (%s) command "
                                   "options." % (self.leave_locale_alone,
                                                 self.can_import_settings))
            # Deactivate translations, because django-admin creates database
            # content like permissions, and those shouldn't contain any
            # translations.
            from django.utils import translation
            saved_locale = translation.get_language()
            translation.deactivate_all()

        try:
            if self.requires_system_checks and not options.get('skip_checks'):
                self.check()
            if self.requires_migrations_checks:
                self.check_migrations()
            output = self.handle(*args, **options)
            if output:
                if self.output_transaction:
                    connection = connections[options.get('database', DEFAULT_DB_ALIAS)]
                    output = '%s\n%s\n%s' % (
                        self.style.SQL_KEYWORD(connection.ops.start_transaction_sql()),
                        output,
                        self.style.SQL_KEYWORD(connection.ops.end_transaction_sql()),
                    )
                self.stdout.write(output)
        finally:
            if saved_locale is not None:
                translation.activate(saved_locale)
        return output