I have a dstack like this:

```
import numpy as np
a = np.array((1,2,6))
b = np.array((2,3,4))
c = np.array((8,3,0))
stack = np.dstack((a,b,c))
print(stack)
#[[[1 2 8]
#[2 3 3]
#[6 4 0]]]
```

and I want to filter out the lists where the 2 element is less then 1.

Something like this:

```
new_list = []
for i in stack:
for d in i[:,2]:
if d>=1:
new_list.append(d)
print(new_list) # [8,3]
```

Doing this only the 2 element is added, but I would like to have all the row, like this:

```
#[[[1 2 8]
#[2 3 3]]]
```

And if I `append(i)`

the result is not the desired one either.

### >Solution :

You don’t need a loop, you can do it with slicing

```
stack[stack[:,2] >= 1]
```