replace element in numpy array pending a different element's value-CodePudding

I have the following numpy array (as an example):

my_array = [[3, 7, 0]
            [20, 4, 0]
            [7, 54, 0]]

I want to replace the 0's in the 3rd column of each row with a value of 5 only if the first index is odd. So the expected outcome would be:

my_array = [[3, 7, 5]
            [20, 4, 0]
            [7, 54, 5]]

I tried numpy.where and numpy.place, but couldn't get the expected results.

Is there an elegant way to do this with numpy functions?

CodePudding user response：

you can do this by indexing as:

my_array[my_array[:, 0] % 2 != 0, 2] = 5

# my_array[:, 0] % 2 != 0   --- Boolean shows modifying rows --> [ True False  True]