Success Rate / Retention

[AustinHasten]

Feature Description
Add a macro for Success Rate / Retention. i.e. the percentage of reviews which you passed rather than failed.

I spent a minute looking through the code to see if I could figure out how to add this myself but it's pretty dense so I just added this function to overview.py:

def true_retention(days_back=0, deck='%'):
    try:
        today = datetime.combine(date.today(), datetime.min.time())
        start_date = today - timedelta(days=days_back)
        start_epoch = start_date.timestamp() * 1000  # nanoseconds to milliseconds or something
        revlog_cmd = f'''
            SELECT
                r.ease
            FROM
                revlog r
                JOIN cards c ON r.cid = c.id
                JOIN decks d ON d.id = c.did
            WHERE
                r.type = 1
                AND r.id > {start_epoch}
                AND d.name like '{deck}'
        '''
        full_revlog = mw.col.db.all(revlog_cmd)
        passed = len([_ for _ in full_revlog if _[0] > 1])
        flunked = len([_ for _ in full_revlog if _[0] == 1])
        if (passed + flunked) < 1:
            return 'No reviews'
        true_retention = passed / (passed + flunked) * 100
        return f'{int(true_retention)}%'
    except Exception as e:
        print(e)
        return 'Error'

And use %eval{true_retention(deck='Deck Name')} as my macro, which seems to be working the way I want it to, but it would be nice if this was integrated.

Great addon, by the way.

[iamjustkoi]

Ope, thanks! Can try to see about adding something that might make this a little easier in the future.

If you wanted to try taking a whack at forking and submitting a PR I can also review that and merge it a little sooner, but I can defs look into combining this with some other requests when I'm more available (hopefully soon, but no guarantees)!

Either way, thanks for suggestion and appreciate the code/write up too!