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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _filename_global(self):

 """Create a .ini filename located in user home directory.
 This .ini files stores the global spyder preferences.
 """

        if self.subfolder is None:
            config_file = osp.join(get_home_dir(), '.%s.ini' % self.name)
            return config_file
        else:
            folder = get_conf_path()
            # Save defaults in a "defaults" dir of .spyder2 to not pollute it
            if 'defaults' in self.name:
                folder = osp.join(folder, 'defaults')
                if not osp.isdir(folder):
                    os.mkdir(folder)
            config_file = osp.join(folder, '%s.ini' % self.name)
            return config_file