Incorrect date when using .when with weekdays

[alxwrd]

hello! 👋

There appears to be an issue with maya.when() when using weekday names.

>>> today = maya.now()
>>> print(today)
'Sun, 15 Apr 2018 16:58:03 GMT'

>>> tomorrow = maya.when("monday", prefer_past=False)
>>> print(tomorrow)
'Mon, 09 Apr 2018 00:00:00 GMT'

dateparser seems to handle this correctly, but only when the setting 'PREFER_DATES_FROM' is set to 'future'.

>>> dateparser.parse("monday")
datetime.datetime(2018, 4, 9, 0, 0)

>>> dateparser.parse("monday", settings={"PREFER_DATES_FROM": "future"})
datetime.datetime(2018, 4, 16, 0, 0)

>>> dateparser.parse("Apr 16")
datetime.datetime(2018, 4, 16, 0, 0)

>>> dateparser.parse("Apr 16", settings={"PREFER_DATES_FROM": "past"})
datetime.datetime(2017, 4, 16, 0, 0)

The default setting for dateparser appears to be "current_period" from dateparser/dateparser_data/settings.py.

As the only way to alter the 'PREFER_DATES_FROM' setting is change prefer_past, there is currently no way to get the future day in this instance.

I'll open a PR with a failing test.

[timofurrer]

Hi! Thanks for contribution!

I'll open a PR with a failing test.

Great! 🎉

@kennethreitz what about exposing the PREFER_DATES_FROM setting from dateparser via the maya.when() API?

Something like:

maya.when('monday', prefer_dates_from='past')

[alxwrd]

@timofurrer I had thought:

-def when(string, timezone='UTC', prefer_past=False):
+def when(string, timezone='UTC', prefer_past=None):

-    if prefer_past:
+    if prefer_past is False:
+        settings['PREFER_DATES_FROM'] = 'future'
+    if prefer_past is True:
         settings['PREFER_DATES_FROM'] = 'past'

     dt = dateparser.parse(string, settings=settings)

This should allow all three of dateparsers options of 'current_period', 'future', and 'past' and not break anything else.

[timofurrer]

Sounds even better!
I'm looking forward to accept the change in the PR you've already made ;)

[timofurrer]

I might have second thoughts about the proposed API.
The thing is, that for me, setting prefer_past=False doesn't intuitively mean that it should prefer the future. It would just mean that not the past should be preferred and therefore the current_period is used. Which isn't the case.

Having both arguments prefer_past and prefer_future available leads to inconsistencies and therefore is not really an option. Which leads us to the prefer_dates_from argument. I know it's kinda verbose but the best I can come up with right now. And thoughts?

[alxwrd]

I agree.

My thoughts behind keeping prefer_past was that it's a non breaking change.

I think because prefer_dates_from is more verbose, it might be nicer.

-def when(string, timezone='UTC', prefer_past=False):
+def when(string, timezone='UTC', prefer_dates_from='current_period'):

    settings = {
         'TIMEZONE': timezone,
         'RETURN_AS_TIMEZONE_AWARE': True,
         'TO_TIMEZONE': 'UTC',
+        'PREFER_DATES_FROM': prefer_dates_from,
     }
-    if prefer_past:
-        settings['PREFER_DATES_FROM'] = 'past'
+
     dt = dateparser.parse(string, settings=settings)
     if dt is None:
         raise ValueError('invalid datetime input specified.')

Let me know and I can push up some changes ✨

[timofurrer]

Yes, let's do that! @kennethreitz any thoughts on that one?

[timofurrer]

Done in #147