# -*- coding: utf-8 -*-
This module offers general convenience and utility functions for dealing with

.. versionadded:: 2.7.0
from __future__ import unicode_literals

from datetime import datetime, time

def today(tzinfo=None):
    Returns a :py:class:`datetime` representing the current day at midnight

    :param tzinfo:
        The time zone to attach (also used to determine the current day).

        A :py:class:`datetime.datetime` object representing the current day
        at midnight.

    dt = datetime.now(tzinfo)
    return datetime.combine(dt.date(), time(0, tzinfo=tzinfo))

def default_tzinfo(dt, tzinfo):
    Sets the the ``tzinfo`` parameter on naive datetimes only

    This is useful for example when you are provided a datetime that may have
    either an implicit or explicit time zone, such as when parsing a time zone

    .. doctest::

        >>> from dateutil.tz import tzoffset
        >>> from dateutil.parser import parse
        >>> from dateutil.utils import default_tzinfo
        >>> dflt_tz = tzoffset("EST", -18000)
        >>> print(default_tzinfo(parse('2014-01-01 12:30 UTC'), dflt_tz))
        2014-01-01 12:30:00+00:00
        >>> print(default_tzinfo(parse('2014-01-01 12:30'), dflt_tz))
        2014-01-01 12:30:00-05:00

    :param dt:
        The datetime on which to replace the time zone

    :param tzinfo:
        The :py:class:`datetime.tzinfo` subclass instance to assign to
        ``dt`` if (and only if) it is naive.

        Returns an aware :py:class:`datetime.datetime`.
    if dt.tzinfo is not None:
        return dt
        return dt.replace(tzinfo=tzinfo)

def within_delta(dt1, dt2, delta):
    Useful for comparing two datetimes that may a negilible difference
    to be considered equal.
    delta = abs(delta)
    difference = dt1 - dt2
    return -delta <= difference <= delta