How can I change 2D array elements with numpy

Question

I want to change only the place in the list called numbers.

So if is numbers=[4,8,11], I want to change 4>>field[0,5]=1,8>>field[0,9]=1,11>>field[1,0]=1

Number in list numbers are 0 to 100. I run this,but it's says 'TypeError: 'function' object does not support item assignment'

How can I solve this? And is there better way to check each number and set 1 at 2D array?

Here is my code

import numpy as np

field = np.zeros((10,10),dtype=int)

def change_numbers(numbers):
    for i in numbers:
        if 1 <= i <= 10:
            i -= 1
            p1_field[0,i] = 1
        elif 11 <= i <= 20:
            i -= 1
            p1_field[1,i] = 1
        elif 21 <= i <= 30:
            i -= 1
            p1_field[2,i] = 1
        elif 31 <= i <= 40:
            i -= 1
            p1_field[3,i] = 1
        elif 41 <= i <= 50:
            i -= 1
            p1_field[4,i] = 1
        elif 51 <= i <= 60:
            i -= 1
            p1_field[5,i] = 1
        elif 61 <= i <= 70:
            i -= 1
            p1_field[6,i] = 1
        elif 71 <= i <= 80:
            i -= 1
            p1_field[7,i] = 1
        elif 81 <= i <= 90:
            i -= 1
            p1_field[8,i] = 1
        elif 91 <= i <= 100:
            i -= 1
            p1_field[9,i] = 1
    print(field)

What is p1_field?

hpaulj
– hpaulj

2020-06-22 04:59:25 +00:00
Commented Jun 22, 2020 at 4:59 — hpaulj
– hpaulj, Commented Jun 22, 2020 at 4:59
Sorry. It's my mistake. field == p1_field

Igor Bond
– Igor Bond

2020-06-22 05:08:31 +00:00
Commented Jun 22, 2020 at 5:08 — Igor Bond
– Igor Bond, Commented Jun 22, 2020 at 5:08

Jordan He · Accepted Answer · 2020-06-22 05:05:22Z

1

To define a function to change the elements of an array, it's better to put the array as an input of the function. This may explain the error message you encountered.
There is a better way to do the job you desired.

Here's the code:

def change_numbers(array, numbers):
    for i in numbers:
        array[(i - 1)//10, i-1] = 1

The last line basically does the whole long 'if' clauses. (i - )//10 returns 0, 1, 2, ... for the conditions in your code.

answered Jun 22, 2020 at 5:05

Jordan He

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