def fetch_val_for_key(key, delete_key=False):

    # first try to find it in the FLAGS
    try:
        if delete_key:
            return THEANO_FLAGS_DICT.pop(key)
        return THEANO_FLAGS_DICT[key]
    except KeyError:
        pass

    # next try to find it in the config file

    # config file keys can be of form option, or section.option
    key_tokens = key.rsplit('.', 1)
    if len(key_tokens) > 2:
        raise KeyError(key)

    if len(key_tokens) == 2:
        section, option = key_tokens
    else:
        section, option = 'global', key
    try:
        try:
            return theano_cfg.get(section, option)
        except ConfigParser.InterpolationError:
            return theano_raw_cfg.get(section, option)
    except (ConfigParser.NoOptionError, ConfigParser.NoSectionError):
        raise KeyError(key)
Return the overriding config value for a key.
dataset/ETHPy150Open rizar/attention-lvcsr/libs/Theano/theano/configparser.py/fetch_val_for_key