How To Make This Matrix in Python

Question

I have this code. Everything works fine.

    P = np.matrix(' \
                  1 0.5 0.5 0.5  \
                  ')          
    print( P )

The output is [[1. 0.5 0.5 0.5]]

I want to make the same matrix without using a string. So I tried

    P = [[ 1, 0.5, 0.5, 0.5 ]]

    print( P )

The output is slightly different. It is

    [[1, 0.5, 0.5, 0.5]]

The second version does not suit my purpose. The following code works with the first version but not the second.

p = (P - 1/2)* 2 * scale()

TypeError: unsupported operand type(s) for -: 'list' and 'float'

So...how do I get the first version of the matrix without making it from a string?

Answer 1

不使用字符串的相同矩阵：

P = np.matrix([[1., 0.5, 0.5, 0.5]])