Scikit-learn - 无法使用 Python 中的 fetch_openml 加载 MNIST 原始数据集

Question

我正在尝试在Python中加载MNIST Original数据集。sklearn.datasets.fetch_openml函数似乎不适用于此。

这是我正在使用的代码-

from sklearn.datasets import fetch_openml
dataset = fetch_openml("MNIST Original") 

我收到此错误-

File "generateClassifier.py", line 11, in <module>
  dataset = fetch_openml("MNIST Original")
  File "/home/inglorion/.local/lib/python3.5/site- 
packages/sklearn/datasets/openml.py", line 526, in fetch_openml
data_info = _get_data_info_by_name(name, version, data_home)
  File "/home/inglorion/.local/lib/python3.5/site- 
packages/sklearn/datasets/openml.py", line 302, in 
_get_data_info_by_name
    data_home)
  File "/home/inglorion/.local/lib/python3.5/site- 
packages/sklearn/datasets/openml.py", line 169, in 
_get_json_content_from_openml_api
    raise error
  File "/home/inglorion/.local/lib/python3.5/site- 
packages/sklearn/datasets/openml.py", line 164, in 
_get_json_content_from_openml_api
    return _load_json()
  File "/home/inglorion/.local/lib/python3.5/site- 
packages/sklearn/datasets/openml.py", line 52, in wrapper
    return f()
  File "/home/inglorion/.local/lib/python3.5/site- 
packages/sklearn/datasets/openml.py", line 160, in _load_json
    with closing(_open_openml_url(url, data_home)) as response:
  File "/home/inglorion/.local/lib/python3.5/site- 
packages/sklearn/datasets/openml.py", line 109, in _open_openml_url
with closing(urlopen(req)) as fsrc:
  File "/usr/lib/python3.5/urllib/request.py", line 163, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib/python3.5/urllib/request.py", line 472, in open
    response = meth(req, response)
  File "/usr/lib/python3.5/urllib/request.py", line 582, in 
http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.5/urllib/request.py", line 510, in error
    return self._call_chain(*args)
  File "/usr/lib/python3.5/urllib/request.py", line 444, in 
_call_chain
    result = func(*args)
  File "/usr/lib/python3.5/urllib/request.py", line 590, in 
http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
        urllib.error.HTTPError: HTTP Error 400: Bad Request

我该如何解决这个问题？或者，有没有其他方法可以将MNIST数据集加载到Python中？

我使用的是 0.20.2 版scikit-learn.

总的来说，我对编程相对较新，所以如果我能得到一个简单的答案，我将不胜感激。谢谢！

Answer 1

试试

mnist = fetch_openml('mnist_784')

我通过 https://www.openml.org/在 https://www.openml.org/d/554 下找到了它

Answer 2

方法fetch_openml（）从 mldata.org 下载数据集，该数据集不稳定且无法连接。另一种方法是手动从原始数据下载数据集。您可以从 Kaggle（mnist 数据）下载数据并运行以下代码

from scipy.io import loadmat
mnist = loadmat("../input/mnist-original.loadmat")
mnist_data = mnist["data"].T
mnist_label = mnist["label"][0]

Answer 3

您可以使用：

mist = fetch_openml('mnist_784', version=1)

Answer 4

fetch_mldata 自 scikit-learn v0.20 起被弃用

测试版

import sklearn
sklearn.__version__

导入数据集

from sklearn.datasets import fetch_openml
X, y = fetch_openml('mnist_784', version=1, return_X_y=True)

例

• https://scikit-learn.org/stable/auto_examples/neural_networks/plot_mnist_filters.html

Answer 5

我也面临着类似的问题。更新 sklearn 的版本对我有用

我刚刚运行了以下命令

conda update scikit-learn

然后要验证版本，您可以执行以下操作

import nltk
import sklearn
print('nltk version: {}.'.format(nltk.__version__))
print('scikit-learn version: {}.'.format(sklearn.__version__))

不要忘记在更新 sklearn 的版本后重新启动内核。

Answer 6

mnist = fetch_openml('mnist_784')