---
title: Find all matching indexes
type: snippet
tags: [list]
cover: tree-roots
dateModified: 2020-11-02T19:27:53+02:00
---

Finds the indexes of all elements in the given list that satisfy the provided testing function.

- Use `enumerate()` and a list comprehension to return the indexes of the all element in `lst` for which `fn` returns `True`.

```py
def find_index_of_all(lst, fn):
  return [i for i, x in enumerate(lst) if fn(x)]
```

```py
find_index_of_all([1, 2, 3, 4], lambda n: n % 2 == 1) # [0, 2]
```