Funciones utiles para trabajar con fechas

dates_helper.py

import datetime

import logging
logger = logging.getLogger(__name__)


class DatesHelper(object):

    def convert_string_to_datetime(self, date=datetime.datetime.now()):
        if type(date) == str or type(date) == unicode:
            date = datetime.datetime.strptime(date, "%Y-%m-%d")
        return date

    def convert_to_initial_datetime(self, date=datetime.datetime.now()):
        """
        Convierte una fecha a la misma fecha con la primer hora del día.
        """
        return datetime.datetime(date.year, date.month, date.day, 0, 0, 0, 0)

    def convert_to_end_datetime(self, date=datetime.datetime.now()):
        """
        Convierte una fecha a la misma fecha con la ultima hora del día.
        Se va al siguiente día y resta un microsegudo
        """
        from dateutil.relativedelta import relativedelta
        current_day = self.convert_to_initial_datetime(date=date)
        return current_day + relativedelta(days=1, microseconds=-1)

    def get_first_day_of_month(self, date=datetime.datetime.now()):
        return datetime.datetime(date.year, date.month, 1, 0, 0, 0)

    def get_last_day_of_month(self, date=datetime.datetime.now()):
        import calendar
        last_day = calendar.monthrange(date.year, date.month)[1]
        return datetime.datetime(date.year, date.month, last_day, 0, 0, 0)

    def calculate_months(self, date=datetime.datetime.now(), months=1):
        from dateutil.relativedelta import relativedelta
        return self.get_first_day_of_month(date) + relativedelta(months=months)

    def get_current_year(self, date=datetime.datetime.now()):
        import calendar
        last_day = calendar.monthrange(date.year, date.month)[1]
        return datetime.datetime(date.year, 1, 1, 0, 0, 0)

    def calculate_years(self, date=datetime.datetime.now(), years=-1):
        from dateutil.relativedelta import relativedelta
        return self.get_current_year(date) + relativedelta(years=years)

    def generate_range_dates_list(self, date_start=None, date_end=None):
        if not date_start:
            date_start = self.get_first_day_of_month()

        if not date_end:
            date_end = self.get_last_day_of_month()

        current_date = date_start
        dateList = []
        #logger.info("start: %s end:%s" % (date_start, date_end))
        while (current_date <= date_end):
            p_date = current_date
            dateList.append(current_date)
            current_date = (current_date + datetime.timedelta(days=1))
        return dateList

    def check_leap_year(self, date_to_check):
        import calendar

        day_of_year = date_to_check.timetuple().tm_yday
        # 60 = dia 29/feb (año bisiesto)
        if calendar.isleap(date_to_check.year) and day_of_year >= 60:
            day_of_year -= 1
        return (day_of_year)