irfpy.util.timeinterval

Time inteval module.

Code author: Yoshifumi Futaana

It provides timeinterval class.

class irfpy.util.timeinterval.timeinterval(start, end, left_open=False, right_open=False)

Bases: object

Time interval class. Time interval and some calculation.

Time interval can be defined.

A simple interval (continuous one block) is instance as follows.

>>> t0 = datetime.datetime(2010, 1, 1, 12, 0, 0)
>>> t1 = datetime.datetime(2010, 1, 5, 12, 0, 0)

>>> tint = timeinterval(t0, t1)
>>> print(tint)
Interval(733773.500000000, 733777.500000000)

The print function print out in the matplotlib’s floating point format (date2num).

One can check if the specific time is inside or outside of the interval as follows.

>>> t0 in tint
True
>>> t1 in tint
True
>>> datetime.datetime(2010, 1, 3) in tint
True

You can add the intervals using “plus” operator.

>>> t2 = datetime.datetime(2010, 2, 1, 12, 0, 0)
>>> t3 = datetime.datetime(2010, 2, 5, 12, 0, 0)
>>> tint2 = tint + timeinterval(t2, t3)
>>> t0 in tint2
True
>>> t1 in tint2
True
>>> t2 in tint2
True
>>> t3 in tint2
True
>>> t2 in tint
False
>>> t3 in tint
False

You can subtract the specific interval using minus operator.

>>> tint3 = tint2 - tint
>>> t0 in tint3
False
>>> t1 in tint3
False
>>> t2 in tint3
True
>>> t3 in tint3
True

The earliest/latest time in the interval can be obtained by left_time() and right_time() methods.

>>> print(tint.left_time())
2010-01-01 12:00:00
>>> print(tint.right_time())
2010-01-05 12:00:00

The interval can be converted to the discrete tuple of times using sampling() method.

>>> t_sample = tint2.sampling(datetime.timedelta(days=1))
>>> for t in t_sample: print(t)
2010-01-01 12:00:00
2010-01-02 12:00:00
2010-01-03 12:00:00
2010-01-04 12:00:00
2010-01-05 12:00:00
2010-02-01 12:00:00
2010-02-02 12:00:00
2010-02-03 12:00:00
2010-02-04 12:00:00
2010-02-05 12:00:00

Developer information

Delegate to the sympy:sympy.Interval.

left()

Return the left-most time (in float).

right()

Return the right-most time (in float).

left_time()

Return the left-most time

right_time()

Return the right-most time

sampling(dt, t0=None)

Return the list of the time with sampling time dt.

Parameters:

• dt – datetime.timedelta object that specifies the sampling time.

• t0 – If given in datetime.datetime object, the start time of the sampling can be specified. Default start time is left_time().

Returns:

Tuple of the time that in inside the interval.

>>> tint = timeinterval(datetime.datetime(2010, 3, 10, 1, 30), datetime.datetime(2010, 3, 10, 1, 40))
>>> tint = tint - timeinterval(datetime.datetime(2010, 3, 10, 1, 31, 30), datetime.datetime(2010, 3, 10, 1, 37, 30))
>>> tint = tint - timeinterval(datetime.datetime(2010, 3, 10, 1, 38, 30), datetime.datetime(2010, 3, 10, 1, 39, 30))
>>> print(tint)
Union(Interval.Ropen(733841.062500000, 733841.063541667), Interval.open(733841.067708333, 733841.068402778), Interval.Lopen(733841.069097222, 733841.069444444))
>>> print(tint.sampling(datetime.timedelta(minutes=1)))
(datetime.datetime(2010, 3, 10, 1, 30), datetime.datetime(2010, 3, 10, 1, 31), datetime.datetime(2010, 3, 10, 1, 38), datetime.datetime(2010, 3, 10, 1, 40))

irfpy.util.timeinterval.empty_interval()

Return timeinterval object with empty interval.

>>> empty = empty_interval()
>>> print(empty)
EmptySet

>>> intvl0 = timeinterval(datetime.datetime(1975, 10, 10), datetime.datetime(1998, 1, 10))
>>> intvl1 = empty + intvl0
>>> print(intvl0)
Interval(721271.000000000, 729399.000000000)
>>> print(intvl1)
Interval(721271.000000000, 729399.000000000)