Issue 34903: strptime %d handling of single digit day of month

strptime correctly parses single digit day-of-month values (at least in the case of "%d %b %Y") which is the behavior I want. However, the documentation seems to say that the field must be two digits with a leading zero if necessary. So I hope that this is the intended behavior rather than just an accidental artifact. If so, then my suggestion is that the documentation be updated to reflect this.

Hi Mike,

Thank you for your issue, but could you add the link to the documentation, just because we have time.strptime and datetime.datetime.strptime.

Thank you,

Sorry for the omission. This refers to datetime.datetime.strptime. The documentation I referenced is: https://docs.python.org/3/library/datetime.html; I did not test 2.7.

So the documentation reads that way because it was originally written for strftime and has been repurposed to represent both. If the code does the right thing then adding a note that strptime supports single digits accurately would probably be a welcome pull request!

In addition to %d there are also other items that support single digit though zero padding is mentioned with strptime as below in the context of strftime : 

>>> import datetime
>>> datetime.datetime.strptime("1/1/2018 1:1:1", "%d/%m/%Y %I:%M:%S")
datetime.datetime(2018, 1, 1, 1, 1, 1)


>>> datetime.datetime.strftime(datetime.datetime(year=2018, month=1, day=1, hour=1, second=1, minute=1), "%d/%m/%Y %I:%M:%S")
'01/01/2018 01:01:01'

I couldn't find exact set of words that can be used to denote that zero padding is optional in strptime and it's returned as zero padded in strftime but if we are changing %d then I propose changing other items too with similar wording.

Thanks

Thanks for the quick response. I would be happy to write a pull request for
the doc change. I've never done this before so it'll take a little while to
get my head around the process, but the "Helping with Documentation"
chapter seems good.

Mike

On Sat, Oct 6, 2018 at 7:09 AM Karthikeyan Singaravelan <
report@bugs.python.org> wrote:

>
> Karthikeyan Singaravelan <tir.karthi@gmail.com> added the comment:
>
> In addition to %d there are also other items that support single digit
> though zero padding is mentioned with strptime as below in the context of
> strftime :
>
> >>> import datetime
> >>> datetime.datetime.strptime("1/1/2018 1:1:1", "%d/%m/%Y %I:%M:%S")
> datetime.datetime(2018, 1, 1, 1, 1, 1)
>
>
> >>> datetime.datetime.strftime(datetime.datetime(year=2018, month=1,
> day=1, hour=1, second=1, minute=1), "%d/%m/%Y %I:%M:%S")
> '01/01/2018 01:01:01'
>
> I couldn't find exact set of words that can be used to denote that zero
> padding is optional in strptime and it's returned as zero padded in
> strftime but if we are changing %d then I propose changing other items too
> with similar wording.
>
> Thanks
>
> ----------
> nosy: +xtreak
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue34903>
> _______________________________________
>

New changeset 6b9c204ee77a0de87d6f51a3d4547a18604cef9e by Paul Ganssle (Mike Gleen) in branch 'master':
bpo-34903: Document that some strptime formats only require 1 digit (GH-14149)
https://github.com/python/cpython/commit/6b9c204ee77a0de87d6f51a3d4547a18604cef9e

New changeset 452b417e34489614b3003b8d08148269096239d5 by Miss Islington (bot) in branch '3.7':
bpo-34903: Document that some strptime formats only require 1 digit (GH-14149)
https://github.com/python/cpython/commit/452b417e34489614b3003b8d08148269096239d5

Thanks for the PR, Mike! This is now merged and backported to Python 3.7, so I believe we can close this issue.

New changeset 35aa0b0ced91cfb48d9dcf80a2ca8683e61f9b3e by Miss Islington (bot) in branch '3.8':
bpo-34903: Document that some strptime formats only require 1 digit (GH-14149)
https://github.com/python/cpython/commit/35aa0b0ced91cfb48d9dcf80a2ca8683e61f9b3e

messages: + msg346002
stage: patch review -> resolved