Are there many of that are `!= version['product']`? If so, why bother doing the date parsing?
Perhaps this is better:
```
for ....
    if params['product'] != version['product']:
        continue
    start_date = isodate.parse_date(version['start_date'])
    end_date = isodate.parse_date(version['end_date'])
    if start_date ...
```
```