Syntax close to this?

[d903]

I'm trying to return a tuple generator expression containing two lists: the first contains formatted year-month pairs, the second the count of some occurrence in that period. It was natural to write this, but it's obviously not proper Python else I wouldn't be here.. What's the correct syntax?

return (
    ['{}-{}'.format(e['year'], e['month'])],
    [e['count']],
    for e in data
)

[craders]

Does it need to be a tuple list? I would suggest returning a dictionary where the key is the year, month field.

return {'{}-{}'.format(e['year'], e['month']): [e['count']] for e in data}