human
Complete this python program:
def get_default_locale_callable():
assistant
#Here is the Python code you requested.

    """Wrapper function so that the default mapping is only built when needed
    """
    exec_dir = os.path.dirname(os.path.realpath(__file__))
    xml_path = os.path.join(exec_dir, 'data', 'FacebookLocales.xml')
    fb_locales = _build_locale_table(xml_path)
    def default_locale(request):
        "\n                                Guess    an    appropiate    FB    locale    based    on    the    active    Django    locale.\n                                If    the    active    locale    is    available,    it    is    returned.    Otherwise,\n                                it    tries    to    return    another    locale    with    the    same    language.    If    there\n                                isn't    one    avaible,    'en_US'    is    returned.\n                                "
        chosen = 'en_US'
        language = get_language()
        if language:
            locale = to_locale(language)
            (lang, _, reg) = locale.partition('_')
            lang_map = fb_locales.get(lang)
            if (lang_map is not None):
                if (reg in lang_map['regs']):
                    chosen = ((lang + '_') + reg)
                else:
                    chosen = ((lang + '_') + lang_map['default'])
        return chosen
    return default_locale