python - sklearn : shapes not aligned 中的值错误

Question

我试图返回我通过程序运行的测试分数，但无论我尝试什么，我都会收到错误:

ValueError                                Traceback (most recent call last)
<ipython-input-19-4b49cb58c813> in <module>()
----> 1 print(model_final.score(X_train, y_train))
      2 print(model_final.score(X_test, y_test))

3 frames
/usr/local/lib/python3.6/dist-packages/sklearn/utils/extmath.py in safe_sparse_dot(a, b, dense_output)
    140         return ret
    141     else:
--> 142         return np.dot(a, b)
    143 
    144 

ValueError: shapes (353,10) and (172,) not aligned: 10 (dim 1) != 172 (dim 0)

完整代码可见here .

Answer 1

问题就在眼前

model_final = model

此语句不会创建模型的副本，它只是执行shallow copy因此，当您更改 model 时，甚至 model_final 也会发生变化。为了避免这种情况，您需要进行deepcopy as

from copy import deepcopy
model_final = deepcopy(model)

这将执行深层复制，并且您对model所做的任何更改都不会影响model_final。