In my python code, I have an array that has different size inside like this

```
arr = [
[1],
[2,3],
[4],
[5,6,7],
[8],
[9,10,11]
]
```

I want to multiply them by 10 so it will be like this

```
arr = [
[10],
[20,30],
[40],
[50,60,70],
[80],
[90,100,110]
]
```

I have tried `arr = np.multiply(arr,10)`

and `arr = np.array(arr)*10`

it seems that both are not working for different size of nested array because when I tried using same size nested array, they actually works just fine

### >Solution :

It is best to just use a nested loop :

```
arr = [
[1],
[2,3],
[4],
[5,6,7],
[8],
[9,10,11]
]
def matrix_multiply_all(matrix,nb):
return list(map(lambda arr : list(map(lambda el : el*nb,arr)),matrix))
print(matrix_multiply_all(arr,10))
```