```from prefect import Flow flatten files = preprocess csv m

Question

```from prefect import Flow flatten files = preprocess csv map flatten list of csvs ``` used to be this ^

Dominic Tarro · Answer

``` task def flatten nested list list gt list return el for arr in nested for el in arr ```

flapili · Answer

just use sum

flapili · Answer

```nested = list range 5 for x in range 5 nested 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 sum nested 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 ```