round_date.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""Datetime floor, ceiling and round utility functions."""


from datetime import datetime, timedelta


def datetime_floor(dt=None, delta=None, datetime=datetime, timedelta=timedelta):
    """Round datetime down to previous timedelta.
    Default: round to previous midnight

    :param dt datetime: datetime to floor (default: datetime.now())
    :param delta timedelta: timedelta to floor against (default: timedelta(days=1))
    :return datetime: datetime rounded down to previous timedelta
    """
    dt = dt if dt else datetime.now()
    delta = delta if delta else timedelta(days=1)
    q, r = divmod(dt - datetime.min, delta)
    return (datetime.min + q * delta) if r else dt


def datetime_ceil(dt=None, delta=None, datetime=datetime, timedelta=timedelta):
    """Round datetime up to next timedelta.
    Default: round to next midnight

    :param dt datetime: datetime to round up (default: datetime.now())
    :param delta timedelta: timedelta to round up against (default: timedelta(days=1))
    :return datetime: datetime rounded up to next timedelta
    """
    dt = dt if dt else datetime.now()
    delta = delta if delta else timedelta(days=1)
    q, r = divmod(dt - datetime.min, delta)
    return (datetime.min + (q + 1) * delta) if r else dt


def datetime_round(dt=None, delta=None, datetime=datetime, timedelta=timedelta):
    """Round datetime to nearest timedelta
    default: round to nearest midnight

    :param dt datetime: datetime to round (default: datetime.now())
    :param delta timedelta: timedelta to round against (default: timedelta(days=1))
    :return datetime: datetime rounded to the nearest timedelta
    """
    dt = dt if dt else datetime.now()
    delta = delta if delta else timedelta(days=1)
    q, r = divmod(dt - datetime.min, delta)
    if r >= (delta / 2):
        q += 1
    return (datetime.min + q * delta)


def main():
    print(datetime_floor(delta=timedelta(minutes=5)))
    print(datetime_ceil(delta=timedelta(minutes=5)))
    print(datetime_round(delta=timedelta(minutes=5)))


if __name__ == "__main__":
    main()