Python深度学习 第二版学习记录

1. 扩展数据的维度 expand_dims

#横向
y=[1,2,3]
y = np.expand_dims(y, axis=0)
y

输出结果：
array([[1, 2, 3]])

# 纵向
y=[1,2,3]
y = np.expand_dims(y, axis=1)
y

输出结果：
array([[1],
[2],
[3]])
2. concatenate 拼接

y=("a","b","c")
Y = np.concatenate([y] * 32, axis=0)
Y

输出结果
array([‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’,
‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’,
‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’,
‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’,
‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’,
‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’,
‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘c’, ‘a’,
‘b’, ‘c’, ‘a’, ‘b’, ‘c’], dtype=‘