Paul Ganssle <p.gans...@gmail.com> added the comment:

According to the sqlite documentation, there's no fundamental datetime type in 
sqlite: https://www.sqlite.org/datatype3.html#date_and_time_datatype


    SQLite does not have a storage class set aside for storing dates
    and/or times. Instead, the built-in Date And Time Functions of SQLite
    are capable of storing dates and times as TEXT, REAL, or INTEGER values


If you have an arbitrary database whose schema you don't know, I'm not sure it 
would be possible to automatically determine that it's a datetime, though it 
appears that Python already provides this functionality by exposing the 
converters "date" and "timestamp" ( 
https://docs.python.org/3/library/sqlite3.html#default-adapters-and-converters )

If you don't know the schema you can't be 100% accurate on which columns are 
datetime, but apparently datetime types that are text will be of the format 
"YYYY-MM-DD HH:MM:SS.SSS", which is a variant of iso8601, REAL columns will be 
Julian day numbers and integers will be epoch time.

If you assume that all your datetime columns will be TEXT and that any TEXT 
column that happens to be a valid date of is a datetime column, then you can 
either use:

    datetime.strftime(text_column, "%Y-%m-%d %H:%M:%S.%f")

Or if you want to be faster and less strict (this will allow several other 
variations on ISO 8601):

    datetime.fromisoformat(text_column)

I would not recommend using `dateutil.parser.parse`, as the dateutil parser is 
intended for taking something you know to be a string representing a datetime 
and getting you a datetime object from it. It is not designed to tell you 
whether something is or is not a datetime.

----------
nosy: +p-ganssle

_______________________________________
Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue35145>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

Reply via email to