numpyの使用におけるよくある誤り

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import numpy as np


# error reporting


# ValueError: all the input array dimensions except for the concatenation axis must match exactly


np.vstack([np.array([[1, 2], [2, 3]]), np.array([])])


# Correct


np.vstack([np.array([[1, 2], [2, 3]]), np.empty((0, 2))])

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data_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9, 10], [11, 12, 13]]


data_array = np.array(data_list)


# data_array.dtype is object


data_list = [[1, 2, 3], [4, 5, 6]]


data_array = np.array(data_list)


data_array[0][0] = 0


# data_list[0][0] or 1