问题
What I am trying to do right now is:
x = x[:, None, None, None, None, None, None, None, None, None]
Basically, I want to expand my Numpy array by 9 dimensions. Or some N number of dimensions where N might not be known in advance!
Is there a better way to do this?
回答1:
One alternative approach could be with reshaping -
x.reshape((-1,) + (1,)*N) # N is no. of dims to be appended
So, basically for the None's that correspond to singleton dimensions, we are using a shape of length 1 along those dims. For the first axis, we are using a shape of -1 to push all elements into it.
Sample run -
In [119]: x = np.array([2,5,6,4])
In [120]: x.reshape((-1,) + (1,)*9).shape
Out[120]: (4, 1, 1, 1, 1, 1, 1, 1, 1, 1)
来源：https://stackoverflow.com/questions/40069220/is-there-a-more-pythonic-elegant-way-to-expand-the-dimensions-of-a-numpy-array