"ImportError:导入_openmp_helpers时加载DLL失败“？

Question

我尝试从nilearn.image导入resample_img，以用于对一些医学图像进行重采样。

import nibabel as nib
import nibabel.processing
from nilearn.image import resample_img

img = nib.load('./dicom_to_nifti.nii')
new_img = nibabel.processing.resample_to_output(img, (2, 2, 2))
new_img.to_filename('nifti_2_2_2')

然而，我一直收到这个错误，说它找不到sklearn模块？我已经通过pip install sklearn安装了。我甚至尝试过卸载所有内容并重新安装，但同样的问题也出现了。我确信这要么是我做错了什么，要么是包有问题。

Traceback (most recent call last):
  File "convert.py", line 9, in <module>
    from nilearn.image import resample_img
    _check_module_dependencies()
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\nilearn\version.py", line 111, in _check_module_dependencies
    _import_module_with_version_check(
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\nilearn\version.py", line 60, in _import_module_with_version_check
    module = __import__(module_name)
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\sklearn\__init__.py", line 75, in <module>
    from .utils._show_versions import show_versions
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\sklearn\utils\_show_versions.py", line 12, in <module>
    from ._openmp_helpers import _openmp_parallelism_enabled
ImportError: DLL load failed while importing _openmp_helpers: The specified module could not be found.. Module "sklearn" could not be found. See http://nilearn.github.io/introduction.html#installation for installation information.
PS C:\Users\craig\Documents\Files\westmead_radiomics> python test.py
Traceback (most recent call last):
  File "test.py", line 3, in <module>
    from nilearn.image import resample_img
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\nilearn\__init__.py", line 72, in <module>
    _check_module_dependencies()
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\nilearn\version.py", line 111, in _check_module_dependencies
    _import_module_with_version_check(
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\nilearn\version.py", line 60, in _import_module_with_version_check
    module = __import__(module_name)
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\sklearn\__init__.py", line 75, in <module>
    from .utils._show_versions import show_versions
  File "C:\Users\craig\AppData\Local\Programs\Python\Python38\lib\site-packages\sklearn\utils\_show_versions.py", line 12, in <module>
    from ._openmp_helpers import _openmp_parallelism_enabled
ImportError: DLL load failed while importing _openmp_helpers: The specified module could not be found.. Module "sklearn" could not be found. See http://nilearn.github.io/introduction.html#installation for installation information.

有什么想法吗？

Answer 1

您的nilearn似乎依赖于sklearn。问题源于pip在导入sklearn时查找_openmp_helpers.py文件的位置中缺少该文件。

我有一个类似的问题，并通过将sklearn降级到0.22以下来解决它。这需要从PyPI存储库中获取它：

https://pypi.org/project/scikit-learn/0.21.3/#files

这有点麻烦，因为我必须安装Python3.7(最新版本似乎可以与sklearn 0.21.3一起使用)和一个C++编译器来构建sklearn (但你可以尝试使用.whl安装)。

Answer 2

我也遇到了同样的问题，并听从了However, import sklearn still gives me error. More details are given below. How do i resolve this?的建议。

在安装"Microsoft Visual C++ Redistributable for Visual Studio2019“并重新启动后，sklearn 0.22运行良好。

> python -c "import sklearn; sklearn.show_versions()"

System:
    python: 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD64)]
executable: python.exe
   machine: Windows-10-10.0.14393-SP0

Python dependencies:
       pip: 19.3.1
setuptools: 40.8.0
   sklearn: 0.22
     numpy: 1.18.0
     scipy: 1.4.1
    Cython: None
    pandas: 0.25.3
matplotlib: 3.1.2
    joblib: 0.14.1

Built with OpenMP: True