最大值的下标
winner = np.argmax(scores)
多个最大值的下标
（np.argwhere返回数组中非0元素的索引）
winners = np.argwhere(scores == np.amax(scores))
winners = winners.flatten()
数组排序并返回原下标
from operator import itemgetter
Lst = np.array([2,3,1,4,5])
indices, L_sorted = zip(*sorted(enumerate(L), key=itemgetter(1)))
元素逐个求平方
err=[num*num for num in Lst]
创建空list矩阵
Lst= [[] for _ in range(K)]
Lst= lsts = [[[] for _ in range(b)] for _ in range(a)]
列表中不重复元素的个数
a = ['lunch', 'afternoon', 'lunch', 'dinner', 'dinner', 'dawn', 'lunch']
print(len(set(a))) # 4
axis=0代表行向，=1代表列向
a = [[1,2],[3,4]]
print(np.sum(a,axis=0))
[4 6]
print(np.sum(a,axis=1))
[3 7]
倒序输出
idx = np.arange(5)
print(idx)
print(idx[::-1])
版权声明：本文为qidangdui4069原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。