Jun 5, 2021 · Assigning values to the loop variables updates their value but does not modify the the original list. To modify the list, you need to reference its elements directly. The code below does this and replaces all 0s in the list with 2s.

Oct 18, 2018 · If you want to replace several values in one go, you could do something like this: Say you'd like to replace 1 with 3 and 3 with 5: ix=np.isin(array, [1,3]) vc=np.vectorize(lambda x: 3 if x == 1 else 5) np.where(ix, vc(array), array)

May 20, 2023 · With the help of others see the below working code snippet that correctly changes the first value in each list greater than 1 to +100 of the value. for l in example_array: for i, x in enumerate(l): if x > 1: l[i] -= 100 break

May 25, 2023 · Replace a For Loop With List Comprehension in a 2D Matrix. In this section, we are going to look at all the possible use cases of for loops in a 2D matrix and also the alternative approach to it. A matrix is an essential data storage in the field of statistics, data processing, image processing, etc

Nov 14, 2021 · As you can read from the code, I want to substitute 1 with 3, 3 with 5 and 5 with -3. I made a for loop with zip so that first in where you have: np.where(a==1,3,a) then np.where(a==3,5,a) and lastly in the last loop np.where(a==5,-3,a) .

Jun 20, 2024 · The provided code demonstrates two different approaches to initializing a 2D array in Python. First, the array arr is initialized using a 2D list comprehension, where each row is created as [0, 0, 0, 0, 0] .

Jan 4, 2025 · We can use for loop to iterate over the list and replace values in the list. We first find values in the list using for loop and if condition and then replace it with the new value. We can also use a while loop to replace values in the list. While loop does the same work as for loop.

Mar 25, 2019 · Your code should be something like this: for row in Array: if N1 in row: # uncomment what you need # row.remove(N1) # remove the value from the row, and therefore from the original Array consisting of such rows # Array.remove(row) # remove entire row …

May 9, 2022 · You can replace elements by using a double index like: array[y][x] if array is list of lists. This is a example: array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]] length = len(array) for y in range(length): for x in range(length): if y % 2 and x % 2: array[y][x] = 1 elif y % 2 == 0 and x % 2 == 0: array[y][x] = 0 print(array)

Oct 22, 2023 · Traditional For Loop: numbers = [1, 2, 3, 4, 5] doubled = [] for x in numbers: doubled.append(x * 2) Map and Lambda Function: numbers = [1, 2, 3, 4, 5] doubled = list(map(lambda x: x * 2,...