how do I change the value of 2d array without knowing its index?
Code:
array = [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
]
for row in array:
for col in row:
if col == 2:
??????????? #this is what im looking for
-
please post a sample input and outputKuldeep Singh Sidhu– Kuldeep Singh Sidhu2020-06-19 16:02:45 +00:00Commented Jun 19, 2020 at 16:02
-
That's not a 2D array.Trenton McKinney– Trenton McKinney2020-06-19 16:04:54 +00:00Commented Jun 19, 2020 at 16:04
Add a comment
|
4 Answers
Try enumerate() in both for loops, which returns index position and value. Then change directly in your array.
array = [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
]
for ir, row in enumerate(array):
for ic, col in enumerate(row):
if col == 2:
array[ir][ic]= 99
Comments
You could use enumerate function:
for row in array:
for i,col in enumerate(row):
if col == 2:
row[i]=3
Comments
here is with numpy 2d array
import numpy as np
array = [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
]
array2d = np.array(array)
array2d
Out[1]:
array([[1, 2, 3],
[4, 5, 6],
[7, 8, 9]])
# Here case if you know or column and/or row
array2d[:,2] = 0 # here is you 'i'..for example set column 2 to 0
array2d
Out[2]:
array([[1, 2, 0],
[4, 5, 0],
[7, 8, 0]])
# Here case if you know condition, for example value '8' -> '88'
array2d[np.where(array2d ==8)] = 88
array2d
Out[3]:
array([[ 1, 2, 0],
[ 4, 5, 0],
[ 7, 88, 0]])
