How to initialize Numpy array of list objects

问题

I'm trying to create a numpy array that looks like

array([[list([]), list([])],
       [list([]), list([])],
       [list([]), list([])]], dtype=object)

This array has shape (3,2). However, whenever I do

np.array([[list(), list()], [list(), list()], [list(), list()]])

I end up getting

array([], shape=(3, 2, 0), dtype=float64)

How do I solve this?

回答1:

You could use the following:

np.frompyfunc(list, 0, 1)(np.empty((3,2), dtype=object))  

We first turn list into a ufunc that takes no arguments and returns a single empty list, then apply it to an empty 3x2 array of object type.

来源：https://stackoverflow.com/questions/57364197/how-to-initialize-numpy-array-of-list-objects