fetch_20newsgroups 数据集导入失败: no handlers could be fetch_20newsgroups

最简单的办法

下载'20news-bydate.pkz', 放到C:\\Users\[Current user]\scikit_learn_data 下边就行.

实际上

scikit learning默认的路径是C:\\Users\[Current user]\scikit_learn_data

也可以添加环境变量'SCIKIT_LEARN_DATA', 程序会在环境变量设置的目录后加scikit_learn_data作为数据集存放的目录

不想用这两个目录的话,可以改site-package/sklearn/datasets/base.py里 的函数: get_data_home(data_home=None)

另一个解决的办法是

1. 手动下载 http://qwone.com/~jason/20Newsgroups/20news-bydate.tar.gz,

存放到scikit_learn_data/20news_home/下

2. 改site-package/sklearn/datasets/twenty_newsgroups.py里的函数: download_20newsgroups

　注释掉下边代码:

    if not os.path.exists(target_dir):
        os.makedirs(target_dir)

    if os.path.exists(archive_path):
        # Download is not complete as the .tar.gz file is removed after
        # download.
        logger.warning("Download was incomplete, downloading again.")
        os.remove(archive_path)

    logger.warning("Downloading dataset from %s (14 MB)", URL)
    opener = urlopen(URL)
    with open(archive_path, 'wb') as f:
        f.write(opener.read())

3. 运行, 程序会自动解压20news-bydate.tar.gz,生成缓存文件20news-bydate.pkz.