Python datetime.datetime.timedelta() Examples

def test_simple_model_with_annual_licence_multi_year(simple_linear_model):
    """ Test the AnnualLicense over multiple years
    """
    import pandas as pd
    import datetime, calendar
    m = simple_linear_model
    # Modify model to run for 3 years of non-leap years at 30 day time-step.
    m.timestepper.start = pd.to_datetime('2017-1-1')
    m.timestepper.end = pd.to_datetime('2020-1-1')
    m.timestepper.delta = datetime.timedelta(30)

    annual_total = 365.0
    lic = AnnualLicense(m, m.nodes["Input"], annual_total)
    # Apply licence to the model
    m.nodes["Input"].max_flow = lic
    m.nodes["Output"].max_flow = 10.0
    m.nodes["Output"].cost = -10.0
    m.setup()

    for i in range(len(m.timestepper)):
        m.step()
        days_in_year = 365 + int(calendar.isleap(m.timestepper.current.datetime.year))
        assert_allclose(m.nodes["Output"].flow, annual_total/days_in_year) 

def parse_age(value=None):
    """Parses a base-10 integer count of seconds into a timedelta.

    If parsing fails, the return value is `None`.

    :param value: a string consisting of an integer represented in base-10
    :return: a :class:`datetime.timedelta` object or `None`.
    """
    if not value:
        return None
    try:
        seconds = int(value)
    except ValueError:
        return None
    if seconds < 0:
        return None
    try:
        return timedelta(seconds=seconds)
    except OverflowError:
        return None 

def dump_age(age=None):
    """Formats the duration as a base-10 integer.

    :param age: should be an integer number of seconds,
                a :class:`datetime.timedelta` object, or,
                if the age is unknown, `None` (default).
    """
    if age is None:
        return
    if isinstance(age, timedelta):
        # do the equivalent of Python 2.7's timedelta.total_seconds(),
        # but disregarding fractional seconds
        age = age.seconds + (age.days * 24 * 3600)

    age = int(age)
    if age < 0:
        raise ValueError('age cannot be negative')

    return str(age) 

def create_sas_token(key_name, shared_access_key, scope, expiry=timedelta(hours=1)):
    """Create a SAS token.

    :param key_name: The username/key name/policy name for the token.
    :type key_name: bytes
    :param shared_access_key: The shared access key to generate the token from.
    :type shared_access_key: bytes
    :param scope: The token permissions scope.
    :type scope: bytes
    :param expiry: The lifetime of the generated token. Default is 1 hour.
    :type expiry: ~datetime.timedelta
    :rtype: bytes
    """
    shared_access_key = base64.b64encode(shared_access_key)
    abs_expiry = int(time.time()) + expiry.seconds
    return c_uamqp.create_sas_token(shared_access_key, scope, key_name, abs_expiry) 

def stop(self):
        """Stop timer and print info message

        The info message will be only printed if `Timer.verbose` is *true*.

        Returns:
            A timedelta object.
        """
        if self.starttime is None:
            raise ValueError("Timer has not been started yet!")

        self.endtime = time.time()

        dt = timedelta(seconds=self.endtime - self.starttime)

        # If no additional information is specified add default information
        # to make the output more readable.
        if self.info is None:
            self.info = 'elapsed time'

        if self.verbose:
            # Connect additional information and measured time for output.
            print('{info}: {time}'.format(info=self.info, time=dt))

        return dt 

def dump_age(age=None):
    """Formats the duration as a base-10 integer.

    :param age: should be an integer number of seconds,
                a :class:`datetime.timedelta` object, or,
                if the age is unknown, `None` (default).
    """
    if age is None:
        return
    if isinstance(age, timedelta):
        # do the equivalent of Python 2.7's timedelta.total_seconds(),
        # but disregarding fractional seconds
        age = age.seconds + (age.days * 24 * 3600)

    age = int(age)
    if age < 0:
        raise ValueError("age cannot be negative")

    return str(age) 

def parse_age(value=None):
    """Parses a base-10 integer count of seconds into a timedelta.

    If parsing fails, the return value is `None`.

    :param value: a string consisting of an integer represented in base-10
    :return: a :class:`datetime.timedelta` object or `None`.
    """
    if not value:
        return None
    try:
        seconds = int(value)
    except ValueError:
        return None
    if seconds < 0:
        return None
    try:
        return timedelta(seconds=seconds)
    except OverflowError:
        return None 

def _total_seconds(td):
    # Python 2.6 doesn't have a total_seconds() method on timedelta objects
    return ((td.seconds + td.days * 86400) * 1000000 +
            td.microseconds) // 1000000 

def _to_seconds(td):
    '''Convert a timedelta to seconds'''
    return td.seconds + td.days * 24 * 60 * 60 

def test_with_offset(self):
        offset = self.offset + timedelta(hours=2)

        assert (self.d + offset) == datetime(2008, 1, 2, 2) 

def fromutc(self, dt):
        """
        The ``tzfile`` implementation of :py:func:`datetime.tzinfo.fromutc`.

        :param dt:
            A :py:class:`datetime.datetime` object.

        :raises TypeError:
            Raised if ``dt`` is not a :py:class:`datetime.datetime` object.

        :raises ValueError:
            Raised if this is called with a ``dt`` which does not have this
            ``tzinfo`` attached.

        :return:
            Returns a :py:class:`datetime.datetime` object representing the
            wall time in ``self``'s time zone.
        """
        # These isinstance checks are in datetime.tzinfo, so we'll preserve
        # them, even if we don't care about duck typing.
        if not isinstance(dt, datetime.datetime):
            raise TypeError("fromutc() requires a datetime argument")

        if dt.tzinfo is not self:
            raise ValueError("dt.tzinfo is not self")

        # First treat UTC as wall time and get the transition we're in.
        idx = self._find_last_transition(dt, in_utc=True)
        tti = self._get_ttinfo(idx)

        dt_out = dt + datetime.timedelta(seconds=tti.offset)

        fold = self.is_ambiguous(dt_out, idx=idx)

        return enfold(dt_out, fold=int(fold)) 

def __init__(self):
        super(tzlocal, self).__init__()

        self._std_offset = datetime.timedelta(seconds=-time.timezone)
        if time.daylight:
            self._dst_offset = datetime.timedelta(seconds=-time.altzone)
        else:
            self._dst_offset = self._std_offset

        self._dst_saved = self._dst_offset - self._std_offset
        self._hasdst = bool(self._dst_saved)
        self._tznames = tuple(time.tzname) 

def test_indexing_over_size_cutoff():
    import datetime
    # #1821

    old_cutoff = _index._SIZE_CUTOFF
    try:
        _index._SIZE_CUTOFF = 1000

        # create large list of non periodic datetime
        dates = []
        sec = datetime.timedelta(seconds=1)
        half_sec = datetime.timedelta(microseconds=500000)
        d = datetime.datetime(2011, 12, 5, 20, 30)
        n = 1100
        for i in range(n):
            dates.append(d)
            dates.append(d + sec)
            dates.append(d + sec + half_sec)
            dates.append(d + sec + sec + half_sec)
            d += 3 * sec

        # duplicate some values in the list
        duplicate_positions = np.random.randint(0, len(dates) - 1, 20)
        for p in duplicate_positions:
            dates[p + 1] = dates[p]

        df = DataFrame(np.random.randn(len(dates), 4),
                       index=dates,
                       columns=list('ABCD'))

        pos = n * 3
        timestamp = df.index[pos]
        assert timestamp in df.index

        # it works!
        df.loc[timestamp]
        assert len(df.loc[[timestamp]]) > 0
    finally:
        _index._SIZE_CUTOFF = old_cutoff 

def test_index_unique(dups):
    uniques = dups.index.unique()
    expected = DatetimeIndex([datetime(2000, 1, 2), datetime(2000, 1, 3),
                              datetime(2000, 1, 4), datetime(2000, 1, 5)])
    assert uniques.dtype == 'M8[ns]'  # sanity
    tm.assert_index_equal(uniques, expected)
    assert dups.index.nunique() == 4

    # #2563
    assert isinstance(uniques, DatetimeIndex)

    dups_local = dups.index.tz_localize('US/Eastern')
    dups_local.name = 'foo'
    result = dups_local.unique()
    expected = DatetimeIndex(expected, name='foo')
    expected = expected.tz_localize('US/Eastern')
    assert result.tz is not None
    assert result.name == 'foo'
    tm.assert_index_equal(result, expected)

    # NaT, note this is excluded
    arr = [1370745748 + t for t in range(20)] + [tslib.iNaT]
    idx = DatetimeIndex(arr * 3)
    tm.assert_index_equal(idx.unique(), DatetimeIndex(arr))
    assert idx.nunique() == 20
    assert idx.nunique(dropna=False) == 21

    arr = [Timestamp('2013-06-09 02:42:28') + timedelta(seconds=t)
           for t in range(20)] + [NaT]
    idx = DatetimeIndex(arr * 3)
    tm.assert_index_equal(idx.unique(), DatetimeIndex(arr))
    assert idx.nunique() == 20
    assert idx.nunique(dropna=False) == 21 

def test_slice_locs_indexerror():
    times = [datetime(2000, 1, 1) + timedelta(minutes=i * 10)
             for i in range(100000)]
    s = Series(lrange(100000), times)
    s.loc[datetime(1900, 1, 1):datetime(2100, 1, 1)] 

def test_validate_n_error():
    with pytest.raises(TypeError):
        DateOffset(n='Doh!')

    with pytest.raises(TypeError):
        MonthBegin(n=timedelta(1))

    with pytest.raises(TypeError):
        BDay(n=np.array([1, 2], dtype=np.int64)) 

def _test_offset(self, offset_name, offset_n, tstart, expected_utc_offset):
        offset = DateOffset(**{offset_name: offset_n})

        t = tstart + offset
        if expected_utc_offset is not None:
            assert get_utc_offset_hours(t) == expected_utc_offset

        if offset_name == 'weeks':
            # dates should match
            assert t.date() == timedelta(days=7 * offset.kwds[
                'weeks']) + tstart.date()
            # expect the same day of week, hour of day, minute, second, ...
            assert (t.dayofweek == tstart.dayofweek and
                    t.hour == tstart.hour and
                    t.minute == tstart.minute and
                    t.second == tstart.second)
        elif offset_name == 'days':
            # dates should match
            assert timedelta(offset.kwds['days']) + tstart.date() == t.date()
            # expect the same hour of day, minute, second, ...
            assert (t.hour == tstart.hour and
                    t.minute == tstart.minute and
                    t.second == tstart.second)
        elif offset_name in self.valid_date_offsets_singular:
            # expect the singular offset value to match between tstart and t
            datepart_offset = getattr(t, offset_name
                                      if offset_name != 'weekday' else
                                      'dayofweek')
            assert datepart_offset == offset.kwds[offset_name]
        else:
            # the offset should be the same as if it was done in UTC
            assert (t == (tstart.tz_convert('UTC') + offset)
                    .tz_convert('US/Pacific')) 

def test_offset(self):
        # Saturday
        last_sat = datetime(2013, 8, 31)
        next_sat = datetime(2013, 9, 28)
        offset_sat = LastWeekOfMonth(n=1, weekday=5)

        one_day_before = (last_sat + timedelta(days=-1))
        assert one_day_before + offset_sat == last_sat

        one_day_after = (last_sat + timedelta(days=+1))
        assert one_day_after + offset_sat == next_sat

        # Test On that day
        assert last_sat + offset_sat == next_sat

        # Thursday

        offset_thur = LastWeekOfMonth(n=1, weekday=3)
        last_thurs = datetime(2013, 1, 31)
        next_thurs = datetime(2013, 2, 28)

        one_day_before = last_thurs + timedelta(days=-1)
        assert one_day_before + offset_thur == last_thurs

        one_day_after = last_thurs + timedelta(days=+1)
        assert one_day_after + offset_thur == next_thurs

        # Test on that day
        assert last_thurs + offset_thur == next_thurs

        three_before = last_thurs + timedelta(days=-3)
        assert three_before + offset_thur == last_thurs

        two_after = last_thurs + timedelta(days=+2)
        assert two_after + offset_thur == next_thurs

        offset_sunday = LastWeekOfMonth(n=1, weekday=WeekDay.SUN)
        assert datetime(2013, 7, 31) + offset_sunday == datetime(2013, 8, 25) 

def parse_date(value):
    """Parse one of the following date formats into a datetime object:

    .. sourcecode:: text

        Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123
        Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
        Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format

    If parsing fails the return value is `None`.

    :param value: a string with a supported date format.
    :return: a :class:`datetime.datetime` object.
    """
    if value:
        t = parsedate_tz(value.strip())
        if t is not None:
            try:
                year = t[0]
                # unfortunately that function does not tell us if two digit
                # years were part of the string, or if they were prefixed
                # with two zeroes.  So what we do is to assume that 69-99
                # refer to 1900, and everything below to 2000
                if year >= 0 and year <= 68:
                    year += 2000
                elif year >= 69 and year <= 99:
                    year += 1900
                return datetime(*((year,) + t[1:7])) - \
                    timedelta(seconds=t[-1] or 0)
            except (ValueError, OverflowError):
                return None 

def utcoffset(self, dt, is_dst=None):
        '''See datetime.tzinfo.utcoffset

        The is_dst parameter may be used to remove ambiguity during DST
        transitions.

        >>> from pytz import timezone
        >>> tz = timezone('America/St_Johns')
        >>> ambiguous = datetime(2009, 10, 31, 23, 30)

        >>> tz.utcoffset(ambiguous, is_dst=False)
        datetime.timedelta(-1, 73800)

        >>> tz.utcoffset(ambiguous, is_dst=True)
        datetime.timedelta(-1, 77400)

        >>> try:
        ...     tz.utcoffset(ambiguous)
        ... except AmbiguousTimeError:
        ...     print('Ambiguous')
        Ambiguous

        '''
        if dt is None:
            return None
        elif dt.tzinfo is not self:
            dt = self.localize(dt, is_dst)
            return dt.tzinfo._utcoffset
        else:
            return self._utcoffset 

def memorized_timedelta(seconds):
    '''Create only one instance of each distinct timedelta'''
    try:
        return _timedelta_cache[seconds]
    except KeyError:
        delta = timedelta(seconds=seconds)
        _timedelta_cache[seconds] = delta
        return delta 

def _to_seconds(td):
    '''Convert a timedelta to seconds'''
    return td.seconds + td.days * 24 * 60 * 60 

def memorized_datetime(seconds):
    '''Create only one instance of each distinct datetime'''
    try:
        return _datetime_cache[seconds]
    except KeyError:
        # NB. We can't just do datetime.utcfromtimestamp(seconds) as this
        # fails with negative values under Windows (Bug #90096)
        dt = _epoch + timedelta(seconds=seconds)
        _datetime_cache[seconds] = dt
        return dt 

def memorized_timedelta(seconds):
    '''Create only one instance of each distinct timedelta'''
    try:
        return _timedelta_cache[seconds]
    except KeyError:
        delta = timedelta(seconds=seconds)
        _timedelta_cache[seconds] = delta
        return delta 

def utcoffset(self, dt, is_dst=None):
        '''See datetime.tzinfo.utcoffset

        The is_dst parameter may be used to remove ambiguity during DST
        transitions.

        >>> from pytz import timezone
        >>> tz = timezone('America/St_Johns')
        >>> ambiguous = datetime(2009, 10, 31, 23, 30)

        >>> tz.utcoffset(ambiguous, is_dst=False)
        datetime.timedelta(-1, 73800)

        >>> tz.utcoffset(ambiguous, is_dst=True)
        datetime.timedelta(-1, 77400)

        >>> try:
        ...     tz.utcoffset(ambiguous)
        ... except AmbiguousTimeError:
        ...     print('Ambiguous')
        Ambiguous

        '''
        if dt is None:
            return None
        elif dt.tzinfo is not self:
            dt = self.localize(dt, is_dst)
            return dt.tzinfo._utcoffset
        else:
            return self._utcoffset 

def memorized_datetime(seconds):
    '''Create only one instance of each distinct datetime'''
    try:
        return _datetime_cache[seconds]
    except KeyError:
        # NB. We can't just do datetime.utcfromtimestamp(seconds) as this
        # fails with negative values under Windows (Bug #90096)
        dt = _epoch + timedelta(seconds=seconds)
        _datetime_cache[seconds] = dt
        return dt 

def _to_seconds(td):
    '''Convert a timedelta to seconds'''
    return td.seconds + td.days * 24 * 60 * 60 

def memorized_datetime(seconds):
    '''Create only one instance of each distinct datetime'''
    try:
        return _datetime_cache[seconds]
    except KeyError:
        # NB. We can't just do datetime.utcfromtimestamp(seconds) as this
        # fails with negative values under Windows (Bug #90096)
        dt = _epoch + timedelta(seconds=seconds)
        _datetime_cache[seconds] = dt
        return dt 

def memorized_timedelta(seconds):
    '''Create only one instance of each distinct timedelta'''
    try:
        return _timedelta_cache[seconds]
    except KeyError:
        delta = timedelta(seconds=seconds)
        _timedelta_cache[seconds] = delta
        return delta 

def __init__(self, tzoffsetfrom, tzoffsetto, isdst,
                 tzname=None, rrule=None):
        self.tzoffsetfrom = datetime.timedelta(seconds=tzoffsetfrom)
        self.tzoffsetto = datetime.timedelta(seconds=tzoffsetto)
        self.tzoffsetdiff = self.tzoffsetto - self.tzoffsetfrom
        self.isdst = isdst
        self.tzname = tzname
        self.rrule = rrule