qq_38177190的博客

1.数组列表之间的相互转换数组转列表[In] a = np.array([1,2,3,4,8]) l = a.tolist() l[Out] [1, 2, 3, 4, 8]列表转数组[In] b = np.array(l) b[Out] array([1, 2, 3, 4, 8])2.改变数组元素的数据类型[In] b = a.astype(float) b[Out] array([1., 2., 3., 4., 8.])遇到再补充...

一.组合1.横向组合（1）np.hstack()[In] a = np.arange(9).reshape(3,-1) a[Out] array([[0, 1, 2], [3, 4, 5], [6, 7, 8]])[In] b = 2*a b[Out] array([[ 0, 2, 4], [ 6, 8, 10], [12, 14, 16]])[In] np.hstack((a,b))[Out] a

Numpy改变数组维度的常用方法1.reshape不会改变原始数组[In] import numpy as np b = np.arange(24) b[Out] array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23])[In] b.reshape(2,3,4)[Out] array([[[ 0, 1, 2, 3],

1.数组和数组之间的运算[In] import numpy as np a = np.array([1,2,3]) a[Out] array([1, 2, 3]) #a为数组。[In] b = np.array([4,5,6]) np.dot(a,b)[Out] 32 #结果为标量32 2.数组和矩阵之间的运算[In] m = np.array([[1,2,3],[2,3,1],[0,1,-1]]) m[Out] array([[ 1, 2, 3],

Numpy中的数组，行/列向量1.array数组2. 行向量3.列向量4.向量和数组之间的相互转换1.array数组[In] import numpy as np[In] a = np.array([1,2,3]) #一个[]对应的是既不是行向量也不是列向量，而是一个数组。[Out] array([1, 2, 3])[In] a.shape[Out] (3,)[In] b = a.T[In] b[Out] array([1, 2, 3]) #数组的转置仍为该数组，可见a并非是一个向量[