NumPy supports boolean indexing

```
a[f]
```

This assumes that `a`

and `f`

are NumPy arrays rather than Python lists (as in the question). You can convert with `f = np.array(f)`

.

NumPy supports boolean indexing

```
a[f]
```

This assumes that `a`

and `f`

are NumPy arrays rather than Python lists (as in the question). You can convert with `f = np.array(f)`

.