CODEWITHSUNDEEP
pythondjango
Ken
Ken

Reputation: 1404

Django queryset to a string

I have a queryset by doing:

chart_data = DetailChange.objects.extra(select={'day': 'date(captured_date)'})\
    .values('item_id__store_id__store_name', 'day')\
    .annotate(total_sale=Sum('amount_sold'))

then I have a queryset like this:

{'day': datetime.date(2019, 6, 24), 'item_id__store_id__store_name': 'Keyboard Pro', 'total_sale': 706.0}
{'day': datetime.date(2019, 6, 25), 'item_id__store_id__store_name': 'Keyboard Pro', 'total_sale': 18.0}
...

now what I want to do is get one single string that combines all the days in it, separated by ",". Like:

"2019-6-24, 2019-6-25, 2019-6-26, ..."

Is there an easy way to get it done?

Upvotes: 2

Views: 1957

Answers (2)

heemayl
heemayl

Reputation: 42107

You can do it with genexp and str.join with , as the separator:

', '.join(str(item['day']) for item in chart_data)

str(datetime.date) i.e. datetime.date.__str__ already returns the date in %Y-%m-%d format so you don't need to do any additional strftime work.

OTOH, if you only need the day field, you should not include item_id__store_id__store_name in values.

Upvotes: 3

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 477607

You can join the an iterable of formated date strings, like:

', '.join(item['day'].strftime('%Y-%-m-%-d') for item in chart_data)

So here we thus will format each day object, like:

>>> dd.strftime('%Y-%-m-%-d')
'2019-6-24'

and we then join these together, separated by a comma and a space (', ').

That being said, if you are only interested in formatting the date, it makes not much sense to first add extra annotations.

Upvotes: 1

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