from numpy.lib.arraypad import _validate_length : ImportError: cannot import name ‘_validate_lengths

@abhinavsagar I'm going to close this for the moment as I think @hmaarrfk is right that this is the same issue as #3649. Specifically, scikit-image 0.14.{0,1} are incompatible with NumPy 1.16.0 and higher. The solution is either:

• upgrade scikit-image to 0.14.2 or 0.15.0, OR
• downgrade NumPy to 1.15.

Please reopen the issue if these options don't fix the problem for you!

source: https://github.com/scikit-image/scikit-image/issues/3906#issuecomment-492039622

即这个问题大概率是因为Numpy版本和scikit-image版本不匹配导致的，解决方法：

把scikit升级到0.14.2以上。

事实上，我根本没有装scikit-image，因此(Anaconda)只需执行下面命令即可解决：

conda install -c conda-forge scikit-image