date_helper.py

from datetime import datetime, timedelta
from nltk import word_tokenize

MOMENTS = {
    'seconds': ['seconds', 'second', 'sec', 'just'],
    'minutes': ['mins', 'minutes', 'today'],
    'hours': ['hours', 'hour'],
    'days': ['day', 'days', 'veröffentlicht', 'Tagen' ],
    'today': ['today',],
    'weeks': ['week', 'weeks'],
    'months': ['month', 'months'],
}

class DateHelper:
    @staticmethod
    def handle_T_format(raw_text):
        '''
        2017-05-26T12:00
        '''
        date_obj = datetime.strptime(raw_text, '%Y-%m-%dT%H:%M')
        return date_obj

    @staticmethod
    def handle_TZ_format(raw_text):
        '''
        2017-05-26T12:00
        '''
        if 'z' in raw_text.lower():
            raw_text = raw_text.upper().replace('Z', '').strip()
        date_obj = datetime.strptime(raw_text, '%Y-%m-%dT%H:%M:%S')
        return date_obj

    @staticmethod
    def handle_timestamp(raw_text):
        date_obj = datetime.fromtimestamp(int(raw_text))
        return date_obj

    @staticmethod
    def handle_format(raw_date, _format):
        date_obj = datetime.strptime(raw_date, _format)
        return date_obj
    
    def handle_moments(raw_date):
        '''
        '''
        if raw_date is None:
            return None
        tokens = word_tokenize(raw_date.lower())
        numbers = [_.strip('+') for _ in tokens if _.strip('+').isnumeric()]
        if numbers:
            number = numbers[0]
        else:
            number = 1
        unit = ''
        for moment, variants in MOMENTS.items():
            for variant in variants:
                if variant in tokens:
                    unit = moment
                    break
            if unit:
                break
        if unit == 'seconds':
            _delta = timedelta(seconds=int(number))
        elif unit == 'minutes':
            _delta = timedelta(minutes=int(number))
        elif unit == 'hours':
            _delta = timedelta(hours=int(number))
        elif unit == 'days':
            _delta = timedelta(days=int(number))
        elif unit == 'today':
            _delta = timedelta(days=0)
        elif unit == 'weeks':
            _delta = timedelta(days=7*int(number))
        elif unit == 'months':
            _delta = timedelta(days=int(number))
        return (datetime.now()-_delta)
                    


def test_helper():
    raw_data = '2017-05-26T12:00'

    date_obj = DateHelper.handle_T_format(raw_data)
    print(date_obj.__class__)


def test_date_moments():
    texts = ['3 seconds ago',
             'minutes a go',
             'just now', 
             '4 hours ago',
             '1 week ago',
             '1 hour ago',
             '5 hours ago',
             'a week ago',
             '3 weeks ago',
             '15+ days ago',
             '30+ days ago',
            ]
    for _text in texts:
        raw_date = DateHelper.handle_moments(_text)
        print(_text, ":", raw_date)

if __name__ == '__main__':
    test_date_moments()