sort elements from 1d array into triangular matrix

I am trying to move the elements from 1d array (55,) made up of

array([1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3,
       4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4,
       5, 1, 2, 3, 4, 1, 2, 3, 1, 2, 1]).

I want to organize this 1d array into a formation like the following:

[[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
 [0, 0, 0, 0, 0, 0, 0, 0, 0],
 [0, 0, 0, 0, 0, 0, 0, 0],
 [0, 0, 0, 0, 0, 0, 0],
 [0, 0, 0, 0, 0, 0],
 [0, 0, 0, 0, 0],
 [0, 0, 0, 0],
 [0, 0, 0],
 [0, 0],
 [0]]

so I want to end up with this:

[[1, 2, 3, 4, 5, 6, 7, 8, 9, 0],
 [1, 2, 3, 4, 5, 6, 7, 8, 9],
 [1, 2, 3, 4, 5, 6, 7, 8],
 [1, 2, 3, 4, 5, 6, 7],
 [1, 2, 3, 4, 5, 6],
 [1, 2, 3, 4, 5],
 [1, 2, 3, 4],
 [1, 2, 3],
 [1, 2],
 [1]]

What is the most efficient way to do this? Also note that I want to do this for a large array of 325K elements to organize it into 807 distinct rows.

If you know exactly how many items you want in your first row you can do this

import numpy as np

a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3,
       4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4,
       5, 1, 2, 3, 4, 1, 2, 3, 1, 2, 1])

b = []
index = 0

for i in range(10, 0, -1):
    b.append(a[index:index+i])
    index += i

for j in b:
    print(j)

which will output this

[1 2 3 4 5 6 7 8 9 0]
[1 2 3 4 5 6 7 8 9]
[1 2 3 4 5 6 7 8]
[1 2 3 4 5 6 7]
[1 2 3 4 5 6]
[1 2 3 4 5]
[1 2 3 4]
[1 2 3]
[1 2]
[1]