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###reshape()
import numpy as np a = np.array([1,2,3,4,5,6,7,8]) #一维数组 print(a.shape[0]) #值为8,因为有8个数据 print(a.shape[1]) #IndexError: tuple index out of range a = np.array([[1,2,3,4],[5,6,7,8]]) #二维数组 print(a.shape[0]) #值为2,最外层矩阵有2个元素,2个元素还是矩阵。 print(a.shape[1]) #值为4,内层矩阵有4个元素。 print(a.shape[2]) #IndexError: tuple index out of range