Nope - 4 months ago 29

Python Question

I know there is a method for python list to return the first index of something

`l = list(1,2,3)`

l.index(2)

>>> 1

Is there something like that for numpy arrays?

Answer

Yes, here is the answer given a Numpy array, array, and a value, item, to search for.

```
itemindex = numpy.where(array==item)
```

The result is a tuple with first all the row indices, then all the column indices.

For example if array is two dimensions and it contained your item at two locations then

```
array[itemindex[0][0]][itemindex[1][0]]
```

would be equal to your item and so would

```
array[itemindex[0][1]][itemindex[1][1]]
```