I have got a python list

```
Year= [‘1997JAN’, ‘1997FEB’, ‘1997MAR’‘1997APR’………………………’2021SEP’’2021OCT’]

```

I would like to extract only years from the above list but not the months

How can I extract only years?

```
Year = [1997,1997,1997,…………………2021,2021]

```