'numpy.ndarray' object 没有属性 'D'

Question

import numpy as np
rowlist = np.array([[0, 2, 3, 4, 5], [0, 0, 0, 3, 2], [1, 2, 3, 4, 5], [0, 0, 0, 6, 7], [0, 0, 0, 9, 9]])

new_rowlist = []
rows_left = set(range(len(rowlist)))
col_label_list = sorted(rowlist[0].D, key=hash)

for c in col_label_list:
    rows_with_non_zero = [ r for r in rows_left if rowlist[r][c] != 0 ]
    if rows_with_non_zero != []:
        pivot = rows_with_non_zero[0]
        new_rowlist.append(rowlist[pivot])
        rows_left.remove(pivot)

for r in new_rowlist:
    print(r)

So i'm following the Coding the Matrix by Philip Klein book lessons and on one of the chapter on Gaussian Elimination, this keeps erroring 'numpy.ndarray' object has no attribute 'D' What I wanted was to be able to sort the matrix called rowlist. Any idea how to overcome this? im doing this on jupyter notebook if it is of any help Thanks in advance!

Answer 1

There is a typo. There is no rowlist[0].D , change the line to the following

col_label_list = sorted(rowlist[0], key=hash)

Also, maybe from next time as a learning process, try and debug a code yourself by locating which line is causing the error (if you read the error message properly).