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Groups > comp.lang.python > #61939

Re: Eliminate "extra" variable

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Tim,

On Sun, Dec 8, 2013 at 2:18 PM, Tim Chase <python.list@tim.thechases.com> wrote:
> On 2013-12-08 12:58, Igor Korot wrote:
>> Also, the data comes from either SQLite or mySQL and so to eliminate
>> the difference between those engines dates are processed as strings
>> and converted to dates for the calculation purposes only.
>> Maybe I will need to refactor SQLite processing to get the dates as
>> dates and not a string, but that's probably for the future. so that
>> dates will be kept as the datetime type until the end of the
>> function. As I wrote the dates will be used as the text for the
>> plotting window axis labels and as the labels they should come out
>> as strings, hence the conversion.
>
> Sqlite can do this automatically if you tell it to upon connecting:
>
>>>> import sqlite3
>>>> conn = sqlite3.connect('x.sqlite',
> ...    detect_types=sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES)
>>>> cur.execute("create table foo (s date);")
> <sqlite3.Cursor object at 0x7f7f31665570>
>>>> import datetime
>>>> today = datetime.date.today()
>>>> cur.execute("insert into foo(s) values (?)", (today,))
> <sqlite3.Cursor object at 0x7f7f31665570>
>>>> cur.execute("select * from foo")
> <sqlite3.Cursor object at 0x7f7f31665570>
>>>> r = cur.fetchone()
>>>> print r
> (datetime.date(2013, 12, 8),)

Interesting.
I'm using datetime rather than the date type for CREATE TABLE() command.
And when running SELECT I still see the b'1998-08-05 23:12:12' string
representation when running my program under debugger.

And it is confirmed by running this:

>>> cur.execute("CREATE TABLE foo(bar datetime);")
<sqlite3.Cursor object at 0x00E1E6A0>
>>> import datetime
>>> today = datetime.date.today()
>>> cur.execute("insert into foo(bar) values (?)", (today,))
<sqlite3.Cursor object at 0x00E1E6A0>
>>> cur.execute("select * from foo")
<sqlite3.Cursor object at 0x00E1E6A0>
>>> res = cur.fetchall()
>>> print res
[(u'2013-12-14',)]
>>>

So, I guess this is a bug in the sqlite3 python module as datetime is
legal data type on the DB engine.

Thank you.

>
>
> Note that it returns a datetime.date, the same as it was defined.
>
> -tkc
>
>
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list

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Thread

Re: Eliminate "extra" variable Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-08 19:10 +0000
  Re: Eliminate "extra" variable Roy Smith <roy@panix.com> - 2013-12-08 15:07 -0500
    Fwd: Eliminate "extra" variable Igor Korot <ikorot01@gmail.com> - 2013-12-08 12:58 -0800
    Re: Eliminate "extra" variable Tim Chase <python.list@tim.thechases.com> - 2013-12-08 16:18 -0600
    Re: Fwd: Eliminate "extra" variable Dave Angel <davea@davea.name> - 2013-12-08 17:36 -0500
    Re: Eliminate "extra" variable Igor Korot <ikorot01@gmail.com> - 2013-12-14 23:49 -0800
    Re: Eliminate "extra" variable Tim Chase <python.list@tim.thechases.com> - 2013-12-15 06:17 -0600
    Re: Eliminate "extra" variable Tim Chase <python.list@tim.thechases.com> - 2013-12-15 06:29 -0600
    Re: Eliminate "extra" variable Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-12-15 12:08 -0500
    Re: Eliminate "extra" variable Igor Korot <ikorot01@gmail.com> - 2013-12-15 14:46 -0800
    Re: Eliminate "extra" variable MRAB <python@mrabarnett.plus.com> - 2013-12-16 00:58 +0000
    Re: Eliminate "extra" variable Igor Korot <ikorot01@gmail.com> - 2013-12-15 18:43 -0800
    Re: Eliminate "extra" variable Dave Angel <davea@davea.name> - 2013-12-15 21:58 -0500
    Re: Eliminate "extra" variable Chris Angelico <rosuav@gmail.com> - 2013-12-16 13:57 +1100
    Re: Eliminate "extra" variable Igor Korot <ikorot01@gmail.com> - 2013-12-15 20:24 -0800

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