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From: Daniel Fortunov <[email protected]>
To: Denis Laxalde <[email protected]>
Cc: Daniele Varrazzo <[email protected]>
Cc: [email protected]
Subject: Re: Latest developments in psycopg3
Date: Mon, 8 Feb 2021 22:38:10 +0000
Message-ID: <CAH1rg6b41jgi2A7qOaUGx1KwkuzD3hNMFWwfcQPKb1Oy5FGVRQ@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>
References: <CA+mi_8btbC_-0KheQ3WYZW81fS4B0MyPyuALihmqHTvqq=6VyA@mail.gmail.com>
	<[email protected]>
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	<[email protected]>

>
> > 1) We can provide a feature to select the type of cursor that is not
> > much dissimilar from psycopg2
> > 2) Do we need DictCursor/RealDictCursor? ISTM that one of the two
> > would be sufficient? Possibly an object inheriting from a Python dict
> > instead of emulating it so that e.g. json.dumps()
>
> Inheriting from dict is strange because we only need read access. So
> rather collections.abc.Mapping, I think.
>

One advantage of using a real dict is that it leaves the door open for the
caller to mutate the results as they consume them. A little impure, I know,
but one practical example I can think of would be where you want to augment
your results with additional data (coming from a different source, outside
the database).

RealDictCursor gives you the flexibility to do this, whereas
collections.abc.Mapping would force you to construct a new dict instance
for every row in order to get the same result.


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