[Python-Dev] iso8601 parsing

[Skip Montanaro]

It's got its own little parsing language, different than the usual
strftime/strptime format scheme, more like what you might see in Excel. I
never worried too much about the speed of dateutil.parser.parse() unless I
was calling it in an inner loop, but arrow.get() seems to be a fair bit
faster than dateutil.parser.parse. This makes sense, as the latter tries to
figure out what you've given it (you never give it a format string), while
in the absence of a format string, arrow.get assumes you have an ISO-8601
date/time, with only a few small variations allowed.

Skip

On Tue, Nov 28, 2017 at 2:52 PM, Paul G <paul at ganssle.io> wrote:

> IIRC, arrow usually calls dateutil to parse dates anyway, and there are
> many other, lighter dependencies that will parse an ISO 8601 date quickly
> into a datetime.datetime object.
>
> I still think it's reasonable for the .isoformat() operation to have an
> inverse operation in the standard library.
>
> On November 28, 2017 3:45:41 PM EST, Skip Montanaro <
> skip.montanaro at gmail.com> wrote:
>>
>>  I think the latest version can now strptime offsets of the form ±HH:MM with
>>>  %z, so there's no longer anything blocking you from parsing from all
>>>  isoformat() outputs with strptime, provided you know which one you need.
>>>
>>
>> Or just punt and install arrow:
>>
>>  import arrow
>>>>>  arrow.get('2017-10-20T08:20:08.986166+00:00')
>>>>>
>>>> <Arrow [2017-10-20T08:20:08.986166+00:00]>
>>
>>>  arrow.get('2017-10-20T08:20:08.986166+00:00').datetime
>>>>>
>>>> datetime.datetime(2017, 10, 20, 8, 20, 8, 986166, tzinfo=tzoffset(None, 0))
>>
>> Skip
>>
>>
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