[utils] Add datetime_from_str to parse relative time (#221)

and `datetime_add_months` to accurately add/subtract months

Authored by: colethedj
This commit is contained in:
colethedj 2021-04-06 18:45:15 +12:00 committed by pukkandan
parent c24ce07a84
commit 9e62f283ff
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2 changed files with 81 additions and 20 deletions

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@ -23,6 +23,7 @@
clean_html, clean_html,
clean_podcast_url, clean_podcast_url,
date_from_str, date_from_str,
datetime_from_str,
DateRange, DateRange,
detect_exe_version, detect_exe_version,
determine_ext, determine_ext,
@ -311,8 +312,18 @@ def test_date_from_str(self):
self.assertEqual(date_from_str('yesterday'), date_from_str('now-1day')) self.assertEqual(date_from_str('yesterday'), date_from_str('now-1day'))
self.assertEqual(date_from_str('now+7day'), date_from_str('now+1week')) self.assertEqual(date_from_str('now+7day'), date_from_str('now+1week'))
self.assertEqual(date_from_str('now+14day'), date_from_str('now+2week')) self.assertEqual(date_from_str('now+14day'), date_from_str('now+2week'))
self.assertEqual(date_from_str('now+365day'), date_from_str('now+1year')) self.assertEqual(date_from_str('20200229+365day'), date_from_str('20200229+1year'))
self.assertEqual(date_from_str('now+30day'), date_from_str('now+1month')) self.assertEqual(date_from_str('20210131+28day'), date_from_str('20210131+1month'))
def test_datetime_from_str(self):
self.assertEqual(datetime_from_str('yesterday', precision='day'), datetime_from_str('now-1day', precision='auto'))
self.assertEqual(datetime_from_str('now+7day', precision='day'), datetime_from_str('now+1week', precision='auto'))
self.assertEqual(datetime_from_str('now+14day', precision='day'), datetime_from_str('now+2week', precision='auto'))
self.assertEqual(datetime_from_str('20200229+365day', precision='day'), datetime_from_str('20200229+1year', precision='auto'))
self.assertEqual(datetime_from_str('20210131+28day', precision='day'), datetime_from_str('20210131+1month', precision='auto'))
self.assertEqual(datetime_from_str('20210131+59day', precision='day'), datetime_from_str('20210131+2month', precision='auto'))
self.assertEqual(datetime_from_str('now+1day', precision='hour'), datetime_from_str('now+24hours', precision='auto'))
self.assertEqual(datetime_from_str('now+23hours', precision='hour'), datetime_from_str('now+23hours', precision='auto'))
def test_daterange(self): def test_daterange(self):
_20century = DateRange("19000101", "20000101") _20century = DateRange("19000101", "20000101")

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@ -3052,33 +3052,83 @@ def subtitles_filename(filename, sub_lang, sub_format, expected_real_ext=None):
return replace_extension(filename, sub_lang + '.' + sub_format, expected_real_ext) return replace_extension(filename, sub_lang + '.' + sub_format, expected_real_ext)
def date_from_str(date_str): def datetime_from_str(date_str, precision='auto', format='%Y%m%d'):
""" """
Return a datetime object from a string in the format YYYYMMDD or Return a datetime object from a string in the format YYYYMMDD or
(now|today)[+-][0-9](day|week|month|year)(s)?""" (now|today|date)[+-][0-9](microsecond|second|minute|hour|day|week|month|year)(s)?
today = datetime.date.today()
format: string date format used to return datetime object from
precision: round the time portion of a datetime object.
auto|microsecond|second|minute|hour|day.
auto: round to the unit provided in date_str (if applicable).
"""
auto_precision = False
if precision == 'auto':
auto_precision = True
precision = 'microsecond'
today = datetime_round(datetime.datetime.now(), precision)
if date_str in ('now', 'today'): if date_str in ('now', 'today'):
return today return today
if date_str == 'yesterday': if date_str == 'yesterday':
return today - datetime.timedelta(days=1) return today - datetime.timedelta(days=1)
match = re.match(r'(now|today)(?P<sign>[+-])(?P<time>\d+)(?P<unit>day|week|month|year)(s)?', date_str) match = re.match(
r'(?P<start>.+)(?P<sign>[+-])(?P<time>\d+)(?P<unit>microsecond|second|minute|hour|day|week|month|year)(s)?',
date_str)
if match is not None: if match is not None:
sign = match.group('sign') start_time = datetime_from_str(match.group('start'), precision, format)
time = int(match.group('time')) time = int(match.group('time')) * (-1 if match.group('sign') == '-' else 1)
if sign == '-':
time = -time
unit = match.group('unit') unit = match.group('unit')
# A bad approximation? if unit == 'month' or unit == 'year':
if unit == 'month': new_date = datetime_add_months(start_time, time * 12 if unit == 'year' else time)
unit = 'day' unit = 'day'
time *= 30 else:
elif unit == 'year': if unit == 'week':
unit = 'day' unit = 'day'
time *= 365 time *= 7
unit += 's' delta = datetime.timedelta(**{unit + 's': time})
delta = datetime.timedelta(**{unit: time}) new_date = start_time + delta
return today + delta if auto_precision:
return datetime.datetime.strptime(date_str, '%Y%m%d').date() return datetime_round(new_date, unit)
return new_date
return datetime_round(datetime.datetime.strptime(date_str, format), precision)
def date_from_str(date_str, format='%Y%m%d'):
"""
Return a datetime object from a string in the format YYYYMMDD or
(now|today|date)[+-][0-9](microsecond|second|minute|hour|day|week|month|year)(s)?
format: string date format used to return datetime object from
"""
return datetime_from_str(date_str, precision='microsecond', format=format).date()
def datetime_add_months(dt, months):
"""Increment/Decrement a datetime object by months."""
month = dt.month + months - 1
year = dt.year + month // 12
month = month % 12 + 1
day = min(dt.day, calendar.monthrange(year, month)[1])
return dt.replace(year, month, day)
def datetime_round(dt, precision='day'):
"""
Round a datetime object's time to a specific precision
"""
if precision == 'microsecond':
return dt
unit_seconds = {
'day': 86400,
'hour': 3600,
'minute': 60,
'second': 1,
}
roundto = lambda x, n: ((x + n / 2) // n) * n
timestamp = calendar.timegm(dt.timetuple())
return datetime.datetime.utcfromtimestamp(roundto(timestamp, unit_seconds[precision]))
def hyphenate_date(date_str): def hyphenate_date(date_str):